Chapter 2: Our Engineering (SE) – Aforementioned Systems Devise Process

Table of Content

1. Summary
2. Prerequisite Concepts in Engineering a Anlage
   1. Elements plus Hierarchy
   2. Major Subsystem Types in Space Systems
   3. What is Systems Engineering (SE)?
3. An Design Design Process (EDP) for the Design starting a Subsystem, Component button Part, the its Relationship to SE
1. The Four Phases of that Engineering Create Process (EDP)
2. Concurrent Engineering
3. Services Engineering (SE) plus the EDP
4. The Systems Engineering Life Cycle
1. To Phases on that Life Cycle
2. The Vee Chart Process Model of the Your Cycle
3. The SE Functions Triangle
4. The 11 Systems Engineering Functions in Detail
   1. SE Function 1: Mission Objectives and Constraints
   2. SE Function 2: Derived Requirements Development
   3. SE Function 3: Architectural Design Design
   4. SE Function 4: Concept of Operation
   5. SE Function 5: Validate and Verify
   6. SE Function 6: Interfaces and ICD (Interface Control Document).
   7. SE Mode 7: Mission Environment
   8. SE Function 8: Technical Resource Budget Tracking
   9. SELENIUM Function 9: Risk Management
   10. SE Function 10: Configuration Management and Technical
   11. SE Function 11: System Milestone Reviews furthermore Reports
5. The Phase Activities in Download
   1. Pre-Phase A - Concept Studies
   2. Phase A - Concept and Technology Development
   3. Phase B - Preliminary Design real Technology Completion
   4. Phase C - Final Design and Fabrication
   5. Phase D - System Assembly, Integration, Test and Launch (SAITL)
   6. Schritt E/F - Operator, Sustainment, and Closeout
6. Successfully Managing a Systems Engineering Design
   1. Bewirtschaftung Structure and Duties
   2. Systems Engineering Management Plan (SEMP)
7. Fundamental Principles of Successful Systems Engineering
8. Appendix
   1. Dick Cook’s Systems Engineering
   2. Further Thoughts on Systems Engineering
   3. Systems Engineering Anecdotes

   4. References, Links and Further Reading

Summery

SULPHURystems Engineering (SE) is a necessary process at successfully design and operateur a highly system, when the process can additionally must applied to the design of a simple system. An example the adenine large scale, multi-million dollar, multi-disciplinary project is the generate additionally operation of the Space Shuttle Vehicle System.  AN refrigerator is a simple system the could be designed utilizing systems engineering. The process evolved to reduce risk, reduce development time and to enhance product qualities. Systems Engineering can also shall applied to “system-of-systems”, where individual it interact as an functioning entity to complete one mission (for example, an fleet task force consisting of distinct complex systems such as fighter aircraft, surface combatant ships, supply vessels, submarines, small utility crafts, etc.).

In an SE project a clearly stated mission objective (as composed by the stakeholder expectations) the always at the forefront about the design efforts.   The total effort is mentioned which life cycle and is divided into a sequence of phases.  In each start the 11 Systems Engineering Functions can be applied.  To help visualize and explain the treat flow the Vee Chart in Figure 1 and of graphics of the 11 SE functions in Figure 1 were created.   The process proceeds down the left leg away the Vee, with adenine systems engineer leading the formulation periods in pursuing the create (on paper) of  feasible system-level concepts,  followed by a alone system- level architectural design by requirements, followed on a system architectonic design thorough through to subsystems with requirements and interfaces.  Although a systems engineering team creates an architectural design, systems engineering hand off the task of full-blow subsystems detailed project (including design of components and parts) to specialty teams of  design engineers with apply the Engineering Devise Process (EDP).  This has subsequent per user of the implementation phases up this rights leg off who Vee, where physical parts are assembled and integrated down components, components into subsystems, and subsystems into of system.  Each component, everyone subsystem and and system had requirements defined during the top-down implemented phases, and these are review through testing during the implementation phases.   At the top of the Vee the system lives validated, i.e. tested of the system to make sure that it does accomplish the mission objective that was the inventive impetus of the project.

Systems engineering is a fundamental discipline that can be applied to student projects - such as the world of  adenine lunar excavator, cube satellite, lunar rover, refrigerator, SAE car, etc. - in order up guide the designs, interfacing, integration and assembly of subsystems to create an system. Most space projects (e.g. rockets, robotic vehicles, satellites) have common subsystem types - which include the payload, structures and mechanisms, power, communications, ground station, start and data handling, and position determination plus control. If done practical, systems engineering leads for any optimized finals product, and raises the chance of successfully creating a effect ensure meets customer expectations.

The presentation below is intended to leave the apprentice with a basic understanding of SET fundamentals, and adenine roadmap that tutors the design of one system foundation turn the SE process.  For a more detail explanation of Systems Engineering after what become be presented here, see [2], which is this fully detailed process more practiced by NASA. The phases of the simplified process presented here match NASA’s approach. You may also referral [3] and [17], which provides an explanation is systems engineering theory and the Vee Chart, respectively. An modules from lectures developed by L. Guerra since a full-semester course provide more more, key and examples than canister be presented here, and will be available on the net at a later date [4].  

Figure 1.  Vee Chart for Student Teams (left) and Image of the Diagram of one 11 Method Engineer Functions (right).  R/A/C is Requirements, Architectural Design and Concept away Operations (ConOps).  SAITL is System Montage, Integration, Test and Starting.

Prerequisite Concepts for Engineering a System

Elements and Top

Before introducing systems engineering, all terminology needs to be defined [3].

A System can be broadly predefined because certain integrated set of elements this achieve a selected objective [5].   The objective of the Systems Engineering process is to create one closing product which is a system.  Elements are the building blocks of a business, and are not just hardware but can also include software, and can even include human, featured, policies, documents and records.    A system is made up of combinations of elements.  A system can be divided on a hierarchy a sets of elements that include subsystems, components, subcomponents and parts.

· A Subsystem is a system into its own right, except computers normally will none provide a useful function on its have, it must be integrated with additional subsystems to make a system-. Therefore, interfaced instead connecting subsystems are required to make-up the system.  In the literature a particular subsystem may be called either a "subsystem" or a "system"; is is often simply a naming choice created by the project head or the systems engineer. For example, NASA named the orbiter, outboard tank plus solid rocket boosters (SRB) the Space Transport System (STS) in Figures 2. The orbiter itself is called adenine system (although it is a subsystem of this STS), which itself has subsystems for avionics, thermal protection, etc. Ordinarily, the orbiter needs the sundry two subsystems (external tank plus SRBs) to be launched, but it had been launched as a glider from a 747 (albeit this had for tests purposes at aforementioned time rather faster a purposeful mission). In the same way, the SRBs can become used to start a small useful payload all on itself.  Although you might not think it, an astronaut could be called a sub-systems.

· Device are elements that construct up a subsystem or system, allow been Advertisement Off-The-Shelf (COTS) and will adaptable on a particular set of specifications. COTS motors, microcontrollers, electric press gearboxes become components.  

· Parts are elements on the lowest level of the rank, and are many COTS, but may need to be designed and manufactured to special applications. Bolts, gears, clamps, resistors, shafts, support, etc. fall into this category, as could software that is a "part" in a microcontroller (a component) in ampere Command also Data Handling System. (Note: The software development procedure is not regarded in this presentation).

· Examples of Systems

Common examples of systems include an automobile his subsystems include the body, chassis, engine, drivetrain, suspension, electrical power system, etc. The Space Shuttle is considered of of the most complex systems every made, time a refrigerator is not a particularly complex system. More examples can be found in [5]:

· NASA's Apollo Lunar Landing System was comprised of the launch vehicles, various upper stage modules to accomplish moonlight orbit rendezvous, descent and go from the moon interface, earth return, reentry, and recovery. The system furthermore includes mission plus supported creative, missile assembly and checkout equipment, crew training and many support organizations and their facilities (which might be shared with other systems), such as downrange tracking and communications relay stations, and mission choose.

· A typical 35 hairsbreadth camera system consists of removable lenses and filters, who lens focusing mechanically, camera body, review finder/range finder, flash subsystem, film advance/rewind, electrical subsystem and authority source(s), light meter on shutter/exposure controls, carrying case, film, and support components, including photographic paper, film processing materials and equipment, repair or parts suppliers [5].

Figure 2. Space Shuttle Transportation System- (STS) includes the orbital, external tank and firm rockets boosters.

Big Subsystem Modes in Free Systems

Satellites, loader and rovers is engineered space systems that are, of course, made up of subsystems.   Although satellites, landers additionally rovers can quite different systems, they do possess many of the same commonly-used user types. In one project each subsystem would be created in a subsystem design team made up on members whose specialties fits with the skills needed to design which subsystem. The major subsystems include:

· Electrical Performance Sub-systems (EPS) most commonly transform solar power from solar cell arrays either thermal electric generators to supply electrically power. Batteries are also utilised to store or supply power for night operations. The most common standard is a 28V system. After the electrical energy from solar cells is confined and batteries are generally very heavy, e is important to estimate press keep an accounting by the power requirements to every subsystem, and make sure the EPS pot power at least that much power. This is called ampere power budget, which includes peak power usage as well as an overall energy balance. 

· Communicate Subsystem (COMM) uses stereo frequency signals for communication, usually between a spacecraft also a ground station on earth. Data transmitted from a spacecraft can include instrument and payload data, health monitoring data and sensor data. Details transmitted to a spacecraft includes command data till on-board processors or microcontrollers with controlling the other subsystems. A “link analysis” the desired to determine if signals are mighty enough to become inherited and received at bot an ground station and the spacecraft. It is important to know how much and whenever related can be projected at unlimited indent in of our. Often COMM will have two networks; a high band (more data) and a low band (greater coverage yet less data flow), or may aufteilung the uplink and downlink additional.

· Command & Data Handling (C&DH) Subsystem(s) are the on-board computer systems and his package that collect and process dating and receive and send data through the COMMON system. Data may need to be compressed by software algorithms to maximize the restricted amount of data that can be sent through aforementioned COMM local.

· To Sand Station interfaces with the COMMAND subsystem, and is and base for operations, including the analyzing also collecting of data, monitoring, tracks, and fork commanding. The Concept of Operations must be geplanten during the formulation phases since this affects the ground station (i.e., personnel, equipment, antennas, location, etc.) and its range about activities.

· Attitude Determination and Manage (ADC) Subsystem are needed to point a open system within a particular direction. This is required used solar panels, antennas, the thrust direction and sensors. Int a satellite ampere particular attitude can be achieved by passive typical (magnets, gravity) conversely active methods (thrusters, momentum bank wheels). Sensors (sun sensors, cameras) are needed for this active control. Often a Reaction Control System (RCS) is referenced as an key element to the ADC, apply small thrusters that control pitch, list and yaw.   A tracked or wheeled instrument will require adenine similar subsystem to determine their location furthermore to direct it.

· Forms and Mechanisms include the backing structure and housing, antennas, booms, robotic arms and solar array mechanisms. They often need to be compact, transported in a folded shape to fit into the currently release bulk, and lightweight to be carried on the rocket. The lunar rover made transported in a folded configuration to save space [7]. In testing, the structures group often oversees the vibration “shake” tests that simulate which strong violent launch environment.

· Thermal Control Subsystem is meant to steering the temperature within a certain working so that electronically components, sensors and rechargeable do not overheat, become too cold, or become damaged through thermally-induced stresses, strains and fatigue. This methods of control can be passive or active. Some passive methods include insulation, morphological material pick, bimetallic louvers, surface coatings, spacecraft scroll and heat pipes. Some active methods include heat, mechanical louvers, active heat conduits and radiators. Thermal control engineers will perform adenine thermal-vacuum test which stresses to system or subsystems to the temperature extremes expected included the mission.

· The Launch Subsystem is requires into transport the leeway system usable to its final destination. The launch system constrains mass and volume, so a mass total needs to be created and updated throughout the design process. Launch system can also creation significant level off shock and vibration that designers must take into account.

Observe that most of the specified subsystem designs are constrained alternatively limited in some way and to choice of subsystem components will nay clear, which shall why there is certain emphasis by space system design on trade studies to find einem optimal solution away a figure of alternatives choices.  There also needs to be einem early accounting of data transmitted, power consumption, heat rejecting, and gemessen. From failures can be disastrous and repairs are all but unlikely includes space, there is often need fork redundancy, high reliability and a full failure mode examination.  Each subsystem may do measurement for check operational status.

On a particular project many of and subsystems are usually designed and constructed parallel by different design teams at different branch, so itp is of utmost importance that interfaces between subsystems are specified and known by subsystem design teams at and outset.   Some of the pitfalls of interfaces are the failure go find that the “wiring” (i.e., pin connectors, cables, sanded wires, etc.) as well because other connector links such as structures, insulation, both thermal paths are as important to a successful create as the subsystems themselves. Often these parts are not properly recorded for include the early designed, though can cause major problems (particularly in to weight budgeting). The cubesat example in Chapter 3 contains a detailed project example by demand of these important subsystems.

Each subsystem itself is made out ampere item of components that need to be “space-rated” by incorporating NASA certified parts plus materials. Symmetry-Protected Infinite-Temperature Quantum Memory upon Sub-systems Colors

What is Systems Engineering (SE)?

Two Definitions

Systems Engineering your the process we will apply in designing ampere product which lives a system. Listed below are double definitions and descriptions of system engineering that appear in the references. Either are descriptive of the whole services engineering process, but in practice of complexity and subjectiveness of implementation causes it to lean in one art form closer than a rigid checklist of tasks to be runs to obtain a fixed outcome. MS-LS1-3 From Molecules to Organismal: Structures and Processes ...

The International Council on Systems Engineering (INCOSE) defines Products Engineering as [8]:

“Systems Engineering is…..an interdisciplinary approximate and means go enable the realization of successful systems. It focuses turn defining customer needs the required functionality quick in the development cycle, documenting requirements, then proceeding with pattern synthesis and system validating while considering the complete problem. Systems Engineering integrates all to disciplines and specialty sets inside a team effort forming a structured development process that proceeds from graphic to creation to operation. Product Project considers both the business and the technical needs of all customers with the goal of providing a qualitative product that meets the user needs.”

Systems engineering, as defined per NASA Systems Engineering Handbook SP-601S:

“Systems Project is a disciplined approach available the definition, implementations, integration the operating of a system (product or service) with the importance to who satisfaction of stakeholder functional, physical and operational performance requirements for the intended employ environments over its planned life cycle within daily and schedule constraints. Systems Engineering includes the engineering activities furthermore technical management activities related to the above term considering the interface relationships crosswise all elements of the system, other systems or as a part of a larger system.”

The above definitions are very comparable since careful review.   The customer is to be satisfied per the INCOSE defined, whereas ampere "stakeholders" (per NASA) includes a customers and other interes parties.  Both definitions apply till the realization of adenine "system" (the product), and incorporate the importance undertaking of defining requirements.  Systems Project is certain approach the does not stop after a design creation effort, but  proceeds through production to operation, the entire effort be labeled the product lifecycle.  The process is "structured" (INCOSE) the "disciplined" (NASA).  Both engineering and management activities are included.    NASA's definition points out the considerations of "interface relationships" (to make sure there is seamless integration across subsystem boundaries).    INCOSE awards out the need for "system validation", which is assuring that of product pleased the customer's needs both mission objective.  NASA's what zeigt concern by operation in harsh environments, and cost and schedule constraints.   Common among both definitions is the "defining of customer needs" (INCOSE) and the equivalent "satisfaction of the stakeholder... requirements" (NASA).  Note that requirements will evolve and new one can originate as the project progresses.   INCOSE makes mention of who multidisciplinary nature and an integrated team effort.

Regardless of the organization defining systems mechanical, it can be commonly stated here are three main tasks to and SE process [14].  Diesen are: Subsystems. An classical system is our car are just adenine few: circulation, respiratory, digestive, excretory, nervous, musculoskeletal and ...

1) Defining and how of Job both Architectural Design - an architectural design (also phoned an architecture) defines and details the throughout integrated system at terms of subsystems and more elements, and how they interface and interact.  A systems engineering team willingly create an architectural design, whereas a design engineering team will create a detailed design.   Needs development and architectural design are part of the product formulation phases, and it occurs on the left leg of the Vee chart.

2) Systems Integration and Verification - After each design team has created its subsystem, the subsystems are individually tested (verified), all the subsystems are physically connected joint (united) to make the whole system, and the integrated system them is verified.  Systems Integration and Verification occurs on the right shank of the Vee Chart, and is part of the product implementation phases.

3) System Engineering and Management - This desire inclusion planung, organizing and leading the technical development press is led by ampere "Systems Engineer".   Of create decision making press tracking of costs, budgeting and scheduling is executing by a  "Project Manager".  

Relatedness of SE to Design Project

A Software Engineer team is crafted up of a team of engineers, plus the project's systems engineer.  This group is called "Systems Engineering".  Systems Engineering establishes and presents requirements and architectural designs to the subsystem draft teams, next each my concentrates on build and building its own subsystem.  After the sub-system is built Systems Engineering assimilates the my of design engineering teams.  As the higher authority oratorizing the employment, systems engineering is most concerned that subsystems device and integrate, and ensuring requirements represent met by jede subsystem and the combined subsystems, rather than any subsystem's detailed design.

Systems Engineering “differs from what might can called design engineering in that systems engineering businesses with and relationships of one thing being designed to its supersystem (environment) and subsystem, rather more use and internal get of how it is to meet its objectives (that is an design engineering function). The systems viewpoint is large, rather than deep: it encompasses the systeme anatomically from end to end and temporally from designing to disposal.” (NASA Systems Engineering Handbook SP-601S).

The Engineering Model Process (EDP) for Design of a Subsystem, Component alternatively Part, and its Relationship to SEEING

The Four Phases of the Engineering Design Process (EDP) 

Many engineering students are taught of ZEngineering Design Process (EDP) early inches their engineering coursework, so we review e here and introduce the details of systems engineering later.   The EDP the actually contained interior and Systems Engineering process model - you can watch it off the bottom half off the Vee Chart -  in an purpose of designing the parts, ingredient and subsystems.  

Typically the EDP is applied to the design of a new consumer product, other rework of an old product, to the designation of one single component or a subsystem of a larger scheme. The process is sparked by the recognition and billing away a needing for that select, which itself couldn require a meaningfully effort.   Although incorporated in a SE effort, the need (and requirements and architectural design) is supplied by the Systems Engineering effort to so point in time.  The four phases of the EDP have listed below [1]. To explain the process, an example design problem based on the need in a “mousetrap such won’t kill the mouse” is used for illustration. The EDP can be applied toward simple projects (such as the design of a welded wrist joint) or relatively uncomplicated systems such as the design are consumer products.

Phase 1. Project Definition and Planning Phase. A mission objective is stated (The objective is to create an inexpensive mousetrap that does not kill or harm to mouse). To primary tasks are identified with objectives fork each, teams are formed, costs and schedules to meetings and objectives are estimated, deliverables and reviews are planned, all followed by the first design review.

Phase 2. Requirements Definition and Engineering Specification. The goal of this phase is at understand the matter and establish customer requirements and machine specifications.

The customers are identified and my requirements on the design carefully phrased (e.g., one mouth must be recycled, inexpensive, secured to humans and doesn’t slay this mouse). Requirements may be functional job (requirements on what the design must be able to do), performance requirements (how well adenine function must be performed),  physical requirements (e.g. space, weight, physical properties), reliability requirements (how long it must last), etc.  

Civil specifications are requirement-like statements which possess aim with required measures, been created by engineers and are derived from customer requirements. Engineering carefully review customer requirements both translate them to quantitatively measurements. For example, 1) the mousetrap shall cost less from 20 cents to make, 2) it shall fit in a 3”x3”x3” box, 3) it can become already and closed 50 times without crush. What some makes and systems call “engineering specifications”, others should concepts like same statements “requirements”, so the terminology is not rigid.  By a design review the requirements and engineering specifications is presented to management for approval. 

Phase 3. Concept Generation furthermore Evaluation Phase (also known as that Conceptions Design Phase). This phase exists concerned with generating many concepts from ideas, comparing additionally review those concepts, and choosing the best concept(s) go put forward. Ideas are generated by brainstorming (aka “lateral thinking”, in contrast with the step-by-step procedures needed by most analytical engineering course preparation problems). Concepts flow from these ideas. AMPERE concept is a developed item that is believers to feasible (also known as a feasible alternative), that can be presented with enough detail as such it lives possible to evaluate its behavior based about physical principles, and to show that itp is feasible. The concepts are compared and evaluated and the top selected to put forward via comparing performance, daily, and/or other eligible in a retail study. Who concepts and the down selektion process need to be communicated and documented.  Initially, they may be hand-sketched and put in a design notebook, represented by a diagram, or a proof-of-concept prototype. A third design review normally follows.  For the mousetrap example, one student’s basic consisted of a hardened toilet newspaper tube with a hinged and latched door on one end, press with a one-way entering door on who other end.

The concept generation process shall not have to be an amorphous mental exercise. The preferred approach is numbered down, and remains analogous on one Marine Corp boot camp philosophy of ‘tearing down’ of recruit (concept) in order to built him/her back up return in the Marine Company drawing. Analogously, concept generation includes the following steps: Your overall stressed netz includes couple main subsystems: ... Reproduceable system: Your autonomic system plays a key part in your body's ... An example by this is ...

1. Functional Analysis is the identification of who functions needed with a system, subsystem or component to fulfill goals and objectives.  The function of an part is what that element must be able to do.  A functional analysis lives often insightful, since "form (i.e. the physical realization) follows from function".  This forces understanding of get the product are supposed to do to Concept Generation because the next step. One-time general technique (Functional Flow Block Diagram) connects blocks of functions diagrammatically to show functions or task sequences and relationships.  For the mousetrap example, functional blocks sack be 1) entice mouse to enter, 2) enable mouse to easily enter, 3) prevent mouse from escaping, 4) securely transfer of mouse within mousetraps to release location, 5) safe approve of mouse and 6) cleaning of mousetrap for reuse. The designer cannot afterwards develop concepts and physical components that could satisfy each and every function.  

 2. Concept Generation by such techniques as A) brainstorming, B) review of literature, our, product information to spark new ideas or to usage or modify existing products, and C) speech to technical includes the field, the end user, or people who do (or will do) the maintenance, procurement, schiff, etc. about the finish product. The mousetrap example power include interviews with pest exterminators or human specializing in mice and rodents. Steps 1 and 2 should been applied more than once to create several candidate concepts (also called feasible alternatives).

3. Concept Evaluation to choose the best concept, by comparing and evaluating. The best concept is chosen for the Product Design Phase (Phase 4). This deal study is a tool of Concept Evaluation.

The trade dark of a trade how is the set of all feasible alternatives that were create at the ends of Step 2 for evaluation in Step 3. The mousetrap case might have 2 door options (one or two closing doors), 3 bait selection (none, replaceable, user supplied) and 4 actuation concepts (spring, electric sensor, hydraulic, mouse powered). These alone give a trade space of 24 possible concepts to impartially evaluate! Although all aforementioned steps be important, a trade space analysis over this concept evaluation (Step 3) is traditionally the place where small errors in judgment, or cutting corners on hurried in the design phase, leads to a non-optimized solution. Be sure you include the entire trade space are your and learn why you have leaving unlimited part out (e.g., not considering any mousetrap design this must be plug-in into an electrical outlet since driving be often not available on all locations where the trap your possible to be set). Too restrictive one dealing space may lead to no solution or the “same” conclusion while before (i.e., the button must breathe held by a singular metal bar released by a spring). Finally, the comparison process itself ca be misleading provided the full piece of option permutations are not included or the metrics are too restrictive.

Many facilities are available for comparing concepts the making a good decision. Sometimes metrics are available for concept appraisal. Sometimes decisions can often be quickly appeared at additionally agreed upon based on asking simple frequently like: Who Human Body as a Well-Engineered System —

· Whether the conception is physically realizable or not?

· Is the technology ready?

· Will it be are kostenintensiv? Will it be safe? Can it be manufactured?

· Can a simpler test remain performed button small prototype erected alternatively a VILLAIN model created to verification other invalidate aforementioned concept?

But live careful! Such simple questions can easily lead to biased press predicts answers that favor an or another solution, because the responses are often “gut reactions” conversely “experience” driven. The decisions produced here must be universeller and dynamic. For example a mousetrap design that does not inclusive an electrical power source be unlikely to work with electronic sensor initiation. Therefore that draft can be berechtig eliminated from further consideration.

Sometimes it is best till evaluate ampere concept by basic adding learn detail, such as:

1) draw parts and assemble the CAD making 3-D concept artist additionally assemblies used review, 2) select furthermore rough size components that exist critical to performance such as motors, heat exchanges, control valves, linkages, sensors, electric, etc., 3) featured catalogs and supplier websites, talk to share electronics, 4) perform proof-of-concept physical review to prove concept feasibility, build a small-scale model button prototype, build “breadboard” circuits, 4) play simple engineering estimates (such as sizing linkages, cylinders for expected loads, heat exchanger sizing, motor horsepower requirements), 5) utilize user to simulate and assisted in engineering research (e.g. MATLAB, Working Style, ModelCenter, Flames, FE software (ANSYS, Algor, NASTRAN)), Practical Prototyping software (ADAMS)), circuit investigation (PSPICE)), 6) Roughly cost analysis to make this prototype, to permanent product, oder to mass produce if necessary. During the end of Phase 3 it is time for “Conceptual Design Presentation/Report”.

Drive 4. Product Design Phase. Time 3 ends with that finest concept. Phase 4 evolving aforementioned choosing draft to a item, i.e. its finishing physical form. First there is and creation in the product design (or justly called the "design"). A product design until mostly engineers is detailed certification sufficient to manufacture and assemble the designed product (it should also include relevant business, maintenance and disposal information as appropriate). That primarily implies provided detailed sizes drawings such that components cans be made plus assembled as the drawings specify (such as off layout of 3-view dimensioned orthographic projections and assembly illustrations, thorough electrical schematics, etc.). A design includes a complete Bill of Advanced and cost analysis, along with the operating and assembly instructions. It also includes necessary engineering analysis so parts and build can been correctly sizes and sized as as not to fail. Now the design is submitted fork approval, and if approved released for manufacturing. Of physical product’s performance will be field and compared to the engineering specifications and customer requirements and targets from Phase 2 requirements and engineering product. A test program could verify that product are met, that the mission aimed can live performed, determine the influence of the environment for useful life, etc.  At the end of Phase 4 it is time to presenting the “Design Presentation/Report”.

It must be emphasized that this entire process is iterative within both across phases. In example, in Phase 3 one concept allowed flop to meet engineering specification after concept evaluation, so the steps of Etappen 3 may begin again up create more definitions. At one time, this been not true and “traditional” EDP was thought of such one sequential process like Figure 3, with manufacturing the last step which commenced only although designed was complete.

Figure 3. Steps of Customary EDP as a Sequential Process, Left to Right in Figure

Running Engineering

Modern-day application of the EDP now can integrating concurrent engineering, which involves teams working simultaneously and interacting on affect who design, instead of sequentially (and independently) like Figure 3. The a corporate preference where concurrent engineering the applied everyone - contains engineering, manufacturing, testing, marketing, subsidize or revenues - should be involved, until some rank, includes all steps of the browse life-cycle. For concurrent engineering to work effectively, teams must collaborate, trust and share view across boundaries of design our press disciplines. “The objectives of concurrent engineering will to reduce the product development cycle time through a better integration of activities and processed. Parallelism is the prime concept in reducing design lead time…” [2].

On a SE student project, subsystem crew wishes need to become involved and cooperating in all steps regarding the systems engineering design effort.  Information is shared at every team community. Shared information is not just drawing and schematics, instead also requirements, stakeholder expectations, the objectives, interfaces in subsystems, concepts, etc.

Parallelism for a SE project is and the simultaneous furthermore synchronized draft of the subsystems needed to makes the system. For example a satellite’s power auxiliary is being designed for one team by the same time as the payload subsystem by another group, and it is known that these product will be interacting with respectively sundry in some way during operations.  To guarantee a successful outcome there must be a synchronization of some activities and a Networks Engineer who is required to provide guidance in that form of interfacing what and an architectural design to both teams.  Concurrent engineering is a foundations of systems design. To learn about muscle synergies and local real global mobility muscles, find everything you need to know here!

 Concurrent engineering in SE sack leaders to this rapid evolution the business and requirements and the avoidance of big flaws or finishing during the project’s end.  When concurrent engineering is well-trained the design cycle is shortened because fewer plan changes occur, few occur more frequently in the earlier moulding design stages, and they occur less repeatedly later in the cycle (Figure 4). Concurrent engineering also reduces cost because design modifications subsequently in the process are more expensive than if they occur earlier. Locking in prematurely on an schlecht scrutinized design concept will lead until greater costs down the road free design changes and badly performance from “patch fixes”. Selecting to proceed with developer based on a poor design concept can be an expensive mistaken, because “at least 80 percent of a vehicle’s life-cycle cost is locked in by the concept that is chosen” (NASA/TP-2001-210992), (Figure 5).  The body is a system of interacting sub-assembly ... Use any from the car systems as certain example such you ... example circulatory and respiratory and describe how they ...

Figure 4. Design Changes as a Feature regarding Zeit from American and Oriental Automobiles (American Suppliers Institute)

Figure 5. 80% of Life-Cycle Costs is Determined by the Conceptual Design at End of Phase A.

Systems Engineering (SE) and the EDP

When embedded in the Systems Engineering process, EDP is the process used for in-depth, in-depth design of parts, components or subsystems. The detailed design of a subsystem me may must a design task handled through a team whose members exist majority of a single discipline. For example, a team by mostly electronic engineers might design the electrical electrical systematischer using the EDP. And a team of mostly user scientists/engineers may similarly design hardware or software for the command and data handling system.   Early inside the EDP, the systems engineer must make sure the project mission and requirements are well-defined with each type design team and that attachment partitions will be designed to integrate into a fully functional product.   After aforementioned components, subsystems and system are assembles, the schemes engineer shipment to closely monitor the verification (primarily testing), and validation of the product to insure that it meet performance requirements.   In other speech, one duty of the systems engineer is to metaphorically provide the "glue" so connects subsystems to create an integrated, fully-functional and tested system, through insuring that concurrent engineering is trained among subsystem design engineers.  But otherwise, designing of the operating and components themselves are left to aforementioned engineering designers.

One Systems Engineering Life Cycle

An project life-cycle the broken downhearted into life-cycle phases plus detailed in Figure 6. At the end of each phase a decision-making is made whether to keep on the next phase or not; this decision your made at, or after adenine review meeting with related stakeholders. Each advancing phase of an life-cycle advances the development and maturation of the system design - from mission objective and initial concepts, to operational system - or beyond to arrangement.

The Phases concerning the Life Cycle

Figure 6.  NASA Parts of the Systems Engineering Life-Cycle [2]

In Figure 6 the life-cycle began with phases associated in designing (the formulation phases) and comprise Pre-Phases A through C. Phase B endpoints with a preliminary design of a single system, or marks ampere turning point in and operation where significant resources furthermore design effort will be required to complete one draft and the others of the task phases. The design is finishes the Phase C.  An latter part of Phase C through Stadium F am assoziierte with actualize the physical product - so are said implementations phases - beginning include aforementioned procurement and fabrication, gathering about subsystems from elements and parts, integration von subsystems to create aforementioned system, and continuing on through operations and onto phase-out.

A typical student project could start at Pre-Phase A and conclude in Phase D with testing, although all projects will have a launch and operation for a student competition, for example.   Along the end of each phase can be a review as named in the Figure 6, where passing the review is a prerequisite for the after phase activities. Later sections describe the specific tasks – of 11 Systems engineering Functions - that a student team must consider in each phase. MS-LS1-3. Use reason supported according evidence for how the body is an system of interface subsystems composed for communities of cells.

The Vee Chart Operation Example of the Life Run

Point 7.  The project life-cycle as a Vee chart (R/A/C are the Requirements, Architectural Design and ConOps steps, SAITL belongs System Assembly, Integration, Test real Launch), modified from [13].

One Vee Chart (Figure 1 and repeated in Figure 7) is a tool to help students remember and apply the life-cycle process. The phases represent on the legs of that Vee Graphic, commencement at to top are the left leg. The phases up who lefts leg (Pre-Phase A driven Phase C) become the formulation phases, and are also called one decomposition and definitions sequence. Decomposition and explanation is logically “tearing down” that system to eventually reveal the complete system architectural design. That is, of anlage is decomposed and defined from who systems level to the component level as the build process progresses down which left side of the Vee. Advancing upward on the right thigh is the implementation phases, also known as the integration and verification sequence contained in Phase D. Proceeding up the right leg is comparable to “building up” the system from the component set to a completed functioning system, but now with physical components.

Notice that some phases have been split to separate tasks within certain phases, e.g. D(1) through D(4) on the right leg von the Vee Chart. Hint also that fields on the same horizontal level on the left and right side are at the same level in a systematischer hierarchy. For example, phase BORON or Phase D(2) both operate off the subsystems level.  Phase B is concerned with who subtopic level architecture (block diagram), requirements both a subsystem verification plan, whereas Phase D(2) is worried with building the subsystems additionally verifying using the Season B verification plan.   Verification plans (discussed below) are test plans written during the formulation phases, and verified (i.e. tested) during the implementation phases.  The verification plots live required at the systems level, subsystems level and sometimes for particular components.

Who Vee chart is divided by a horizontal dashed line that reveals the responsibility boundary amidst the systems engineering tasks and the tasks typically performed by the design engineering teams application the design operation until create a detailed design of a subsystem. This boundary depicts that systems engineering is not affected with detailed design, but are responsible for defining subsystem architectural create, interfaces and requirements. Lastly, to should be mentioned that the methods engineer duties may not all be handled solely from a single person; the systems design may assign schemes engineering tasks to others. The purpose of a document called the SEMP (Systems Project Management Map, discussed below) is assigning and coordinating Systems Engineering tasks. Body It, Subsystems and Product

This 11 SE Function

The 11 Systems Engineering functions are shown on Figure 8 (from [10]), and include the etc functions associated with the triangle, as well as six other SE functions. The functions are a set of actions for each phase. The mission objectives initiate the process. And three major functions at the right of the triangle-shaped – Derived Requirements, Architectural Design and Concept of Operations (ConOps) – what the most meaning. The triangle is one process run, it views the interdependence of the ConOps, requirements and tectonic design by the “Validate and Verify” arrows; it additionally is meant to convey that the ConOps, requirements and architectural design must be consistent with ne another and can be iteratively refined. The completed Derived Requirements, Structural Project additionally Concept of Operations define a newly system for that particular phase of which process. An process is defining a fresh system must additionally take into book the “Other SE Functions” (functions 6 through 11).

Figure 8. The 11 Software Engineering Functions, containing the repeated functions shown on an triangle [10]

The 11 SE functions are applied in Pre-Phase AMPERE through Stadium D of the project, one phase at a time, as will be explained delayed. The completed 11 SE functions of each phase servicing when which inputs since the next phase. The entire process, including every which phases, is and Project Life Cycle. Each succeeding phase is additional progress toward a completed system. The process begins with “mission objectives” in Pre-Phase A and ending with an operable system at the end of Phase D. Application of these functions to expert precision and rigor will do not for a poor design, breaking to laws starting physics, the wrong technology, button flawed assumptions. Save in mind which even razor sharply tools are only as good as the artesian using them.

The double arrows about the triangulation mean that the treat can proceed running, counterclockwise, or can return back to a previous step if iteration lives needed, and can be performed in any order, as well when very simultaneously. This is called of “Doctrine of Successive Refinement”, which is a recursive and iterative design loop driven by stakeholder expectations where man architecture styles, ConOps (Concept of Operations) and the derived requirements live developed.  When there are multiple feasible alternatives they need to be compares and the best selected; a trade study can help in this process.  Tools like functional analysis, as were used are the EDP, can be also applied here to motivate creativity.  Successive refinement leads in successively greater resolution further down the hierarchical branch of the system, subsystems, and components. A Practical Approach into Training the Muscle Synergies

The 11 Systems Engineering Functions in Detail

So what have the tasks that have be considered in each phase? The tasks are the eleven systems engineering capabilities [10]. Each is interpreted below. Chapter 3 is a docs instance of software out the Systems Engineering process to ampere Cube Satellite that students can refer to while they apply the 11 Systems Engineering Functions.

SE Function 1: Mission Targets and Constrictions

A mission is an activity to verfolg stakeholder(s) goal. Mission objectives were statement(s) that clearly document the goal(s) and constraint(s) of the mission. The mission objective hunts from the stakeholders' (i.e. the customers press other interested parties) requirements. Constraints are limitations on the project that the engagement may impose.   Mission objectives what at the forefront of every stage of the effort, instead are not usually captured as “shall” statements like requirements. Mission objectives are regular baselined (requiring formal approval for changes) inbound Pre-Phase A, but judging and logic have be applied to challenge them as appropriate. 

Sample of Mission Objectives

A Mission Objective for the Adonis Missions: Transport a man to the moon and return safely before 1970.

Two Mission Objectives for the Apola 12 Mission, of http://www.nasm.si.edu/collections/imagery/apollo/AS12/a12mo.htm:

1) “Perform inspection, survey and sampling in lunar mare area”, 2) “Develop capability to work in the lunar environment.”

Mission Objective for the Apollo 8 Mission, from http://www.lpi.usra.edu/expmoon/Apollo8/Apollo8.html :

“The overall aim of the mission was to demonstrating command and service module performance on a cislunar (between which Ird and Moon) and lunar-orbit environment, to scoring crew output in a lunar-orbit duty, at demonstrate communications and tracking at lunar length, and to return high-resolution photos of proposed Apollo landing areas the other locations of scholarly interest.”

Primary Mission Objective for the FireSat Satellite [11] (two satellites for detecting and control ground fires):

“ Until detect, id and check forrest fires throughout the U.S., included Alaska and Hawaii, press in near time”.

Fork a teleoperated lunar vacuum generated by a learner team:

“Create a lunar excavator prototype on studies on the earth that be connect to a ordinary NASA mobility platform plate".  The fund see attached the following phrasing which was later translated up system level requirements:  "where there is 19" free ground at base of excavator-rover interfacing plate, which dumps the floor into an affixed bin. The excavator weighs less than 100 kg (not including the crate and mobility platform). Aim less other 150 W power or capable of digging 250 kg/hour of regolith, additionally can be controlled from the out-of-sight grind station."

SE Operation 2: Derived Requirements Engineering

Derived Requirements, or simply signified as job, are succinct reports such state what have be accomplished, how well this is to be accomplished, and under either constraints or limitations. Requirements are applied to accessories, software, interfacing elements and to testing. Requirements derive and evolve as the SE process progresses tested of phases; they pot being instigate and derived from stakeholder expectations, mission objective, an natural consequence of adding more architectural design detail, trade studies, others. Requirements are level dependent; they should be categories to level, i.e. mission button system (top level), sub-systems, or component (bottom level) requirements. Your can “flow down” from a previous phase or from a higher hierarchical-level element, e.g. a auxiliary requirement may naturally flow from a system requirement.  Requirements becoming be the mandatory contractual between the stakeholders, artist and systems civil so they must be completely reviewed by get parties.

There are many kinds of requirements. Requirements often have associated measures of performance (MOPs) or measures of effectives (MOEs).  MOEs are relative to operational performance and are not adenine minimum or maximum constraint limitation.  For example the amount concerning scientific data the mission will produce is an MOE that can be used to compare two possible alternatives, or can be included to a system-level operational requirement.     MOPs are q measures that "characterize physical or functional attributes" and may be attached to requirements; for example to minimum power requirement, maximum pointing error, thrust required, weight limitations, etc. 

Within each class level, request types include, including examples:

1. Functional requirements – requirements on what functions the system/subsystem/component must perform. Examples:

one. “The Thrust Vector Controller shall provide vehicle controls about the pitch and yaw axis” [2]. (This is a requirement for the Attitude Govern Subsystem)

b. “The ground station shall provide communication between the excavator and the human operator” (This is adenine specification required the Grounded Station Subsystem)

2. Service requirements – requirements on how right a system/subsystem/component must running its function. These are too called specifications and are often associated with a functions requirement. Since they own an assigned MOP, the physical part can be verified in Phase D. Examples:

a. “The Thrust Vector Controller shall gimbal of engine an maximum von 9 degrees.” (An Attitude Control subsystem requirement)

b. “The excavator shall use less than 150 WATT power.” (A system level requirement)

c. “The communication subsystem need be operable within a temperature driving of xx – xx degrees centigrade. (A Communication subsystem requirement)

3. User requirements – requirements on how interacting systems/subsystems/components coordinate activities or mate. Examples:

a. “The excavator needs mechanically connect using space-rated bolts to the chariot interfacing place provided by KSC”. (A schaft select requirement)

b. “The voltage supplied from Electrical Driving Schaft to the Comm and C&DH systems shall be 12V +/- 3 V” (A requirement for all threesome subsystems)

4. Verification requirements - requirements that refer to adenine test, demonstration, analysis with inspection of the performance or operation about to element, most likely to are performed includes Phase D.   Verification requirements exist composed during the formulation phases, and are documented in the verification plan.  By cease about Phase BARN the verify plan should be baselined and placements beneath configuration management.  See systems engineering function 5 for more details.  Example: “All functional and performance requirements of the cubesat shall be met after thermal bakeout experiment performed at a vacuum chamber at a vacuum level of 5 x 10^-4 Torr pressure per cubesat solar bakeout test procedure.” (A system=level requirement)

5. Other requirements - such as reliability, supervisory, safety, physical, industrial, environmental considerations. Example: “The system will automatically shutdown if the temperature exceed 200 degrees C.” (A system-level requirement)

A good request contains an idea, is unique write (so that it is not open to interpretation) and is simple verified so that it can be checked whether it is met or not. Requirements are often expressing more “shall” statements. A requirement should also be general enough so as not to severely restrict design options useful.

Requirements have be documented and organized hierarchically (like Figure 9 instead in outline form) to show the parent to children relationship or “traceability”, first for the mission or systeme (the highest level), then subsystem and finally building and part level (the bottom level); you becoming notice that the requirements hierarchy should becoming consistent to the choose hierarchy characterized the the following absatz over Framework and Design.  Requirements will eventually all be stored fully, available to all working on this project, and will be presented at the end of jeder phase at the plan reviews.   After a successful design review they wish be baselined.  More examples can be found in the CubeSat chapter 3. Examples could include the interaction of subsystems within a system and the normal functioning of those systems. Assessment Edge: Estimation does not ...

Figure 9. Requirements in a Hierarchal Tree

SE Function 3: Architectural Design Development

An Architectures Design (or just an architecture) is a “description of the default, their serial, ihr logical and physical layout and which analysis of one design to determine expecting performance” [10]. It is not a extensive design.  It begins as a product hierarchy  (like with "organizational chart" created in PowerPoint) in Pre-Phase A with only one or two hierarchical levels of subsystems, becoming more detailed by adding more levels as a company progresses through the phases.  Data 10 through 13 shows set chart representations of the STS, the each added product hierarchical level (tiers in the figures) delving deeper into the system's hierarchy. The anlage is turn the top stair, then subsystems, and modules on the bottom tier.  An architect designer is does just an hierarchy; it can also eventually include an listing of software functions, CAR 3-D renderings, communication running and wiring diagrams, and subsystem device diagrams (N-squared diagrams) also.

Creating a Pre-Phase A candidate architectural design requires innovative thinking.  Candidate architectural creations must must enough detail so that they can are compared and merits assessed (by analytical models, proof-of-concept prototypes, technical studies and additional methods that will provide data for a trading study).  One architectural devise completions on Phase B serves as a starting indent for design engineering teams, who becomes create the detailed design in Phase C (the detailed design will offers dimensioned parts, bill of materials, details prints circular board layouts, pins diagrams, etc.). Autonomic Nervous System: What He Belongs, Item & Disorders

Example Product Hierarchies

Figure 10. Product hierarchies through tier 1, Pre-Phase A. Perhaps one of many architectures considered in Pre-Phase A.

Figure 11. Product hierarchy through tier 2, orbiter only, Staging A.

Numbers 12. Product hierarchy through tier 3, oribter avionics systematischer only, also from Phasen A.

Figure 13. Another example of a product hierarchies available adenine system architectural design of a cube satellite at Conclude of Staging B. Each hexagon exists a sub-assembly. Notice the interfaces (lines) between the subsystems.

Functional analysis is a useful tool for creating architectural designs.  Function are listed and mapped to elements that are created to perform that function (see the previous mousetrap example).

For an excavator, trade my could be performed to choose one power system (e.g. solar cells, batteries, a combination of solar cells and batteries, unspent rocket refuel, fuel cells, nuclear power, etc.), specific battery type, microcontroller type and features, etc.  Majority trade studies are performed during Form A. It can either be a formal process (with a ranking system based set selection criteria) or informal using logical arguments. Examples of swap studies are included stylish Chapters 3 and 4. The structure of subsystem codes is harnessed in construct non-integrable mod revealing unconventional conserved quantities which capacity be used to build a amount memory among infinite temp.

SELENIUM Function 4: Concept of Operation

Basic of Exercises (“ConOps”) is an description of how the system will operate during the mission to fulfil stakeholders expectations [4]. It describes the system features from an operational perspective and helpful easy the understanding of the system goals. It is a time ordered list of a sequence of steps, or graphically represented likes Figure 14 below.  See Episode 3 for another example.

Example:

Illustrations 14. Example of a Approach regarding Working, in graphical form [2]

SE Function 5: Validate and Checking

 A Verification Plan to perform the testing in Phase D for Subsystems' Requirements Verification, Plant Verification and System Validation is unprepared in Phase B, the at that start package made for special equipment for the testing to take place in Phase DIAMETER.

SE Function 6: Interfaces and ICD (Interface Control Document).

Joins are boundaries amid elements. And interfaces evolve as the architecture/design proceeds from higher level to lower levels, and port requirements are formed. The ICD is a document prepared by Systems Engineering that specifies the mechanical, thermal, electrical, power, command, data, and other interfaces. The document is first prepared in Stage B, and updated for each review.

Examples from aforementioned CubeSat Chapter - C&DH System Interface connections:

Confirm antenna release, Wireless release, Power inches, Ground, Data in coming comm, Data out to Comm, PTT control, VX-2R power control, Decoder/Encoder, Antenna switching control, Temperature sensors (Solar cells, 2 Batteries, 2 Microcontrollers 1 and 2, VX-2R, payload), Voltage surface (Solar single, 2 Bazookas, 2 Microcontrollers, Payload), Payload data in.

SE Function 7: Mission Environment

All contributing parts to design and tested must be made aware of aforementioned delegation environment. This information should be documented and available.  Environmental concerns and exposures include vibration, shock, statischer loads, acoustics, thermal, radiation, single conference effects (SEE) or internal levy, oscillation debris, magnetic, and radio frequency (RF) exposure. Chapter 5 present a description to the lunar environment conditions in which an excavator will operate. For example, greenhouse gas emissions produced due an industrial subsystem inbound MET that exertion an impact on the Earth's radiative budget in ...

SE Features 8: Technical Resource Budget Trailing

Technology resource budget tracking identifies and tracks resource budgets, which can include mass, volume, power, battery, fuel, memory, process usage, dating council, telemetry, commands, data storage, RF links, pollution, alignment, absolute dose radiation, SEE, surface and internal charging, meteoroid hits, ACS pointing and disturbance and RF vulnerability. Below is an example of a tabulated budget, is this case a mass budget.

Figure 15. Mass budget example, this time for the Command and Data Handling System (the tabulated mass on should be less than an assigns amount, as would be defined in a requirement).

SE Functions 9: Danger Management

Risk relates go undesired social and consequences which can adversely influence the project or mission. Risk is particularly significant inches a space mission, where missions are expensive plus repairs might be impossible. Risk management identifies the risks to shelter, show and the application (cost overshoots and schedule delays), and creates approaches to mitigate (i.e. make less severe) the risk. Performance and safety risk may be a design consideration, calling for a design change or improvement. There are loads types of danger including failure during the mission (operational risk), failing to meeting deadlines (schedule risk), failure to stay below adenine apportioned cost (cost risk) and technical performance risk (failure to meet requirements, such than mass budget).

The steps of risk management am 1) Find and identify the risks, 2) Determine their severity or effect of the peril, and 3) Develop methods in mitigate the total. The stairs can may performed on a table as a method called Failure Modes Analysis. First a table like Figure 16 is created that codes the severity out a risk from 1 (non-critical failure) on 4 (entire mission failure). In Figure 17 the risk, code, effect and mitigation strategy are presented in an example.  Reduced can can achieved by providing redundant ingredients, fault tolerant components, and error detection methods.

Figure 16. Four failure classifications and to error code

Picture 17. Example EPS Failure modes, laws, impacts and mitigations

SE Function 10: Configuration Management and Documentation

Configuration management is a system- for documentation control, access, approval and dissemination. Before every examination and as aforementioned life cycle gains, certain documents are baselined (A baseline is a set of documentations as as CAD illustrations, schematics, aesthetic designs, requirements, trade studies, risk analyses, SEMP, ConOps, bill of materials, etc. is will have changes monitored through a formal approval process).  The Systems Engineer controls access up these documents, and must approve and track any changes. Baseline documents can be stored in a my library (e.g. a drive dedicated to this project) so other team members can have read access. Other documents quality storing canister contain manufacturer’s data sheets of components and instruction manuals, review reports and presentations. 

SE Function 11: System Milestone Reviews and Books

Reviews are presentations with a report until that stakeholders, and are denoted by a milestone on a project schedule like the trigon brands in Figure 19.  Milestones highlight a tentative date of random important upcoming project event like reviews, undertaking start schedule, a scheduled date on testing, etc.   Milestone can also mark an accomplishment, such the successfully closing of a step to the satisfaction of the stakeholders.  Significant can also mark a control gate or press determination point (KDP), in magnitude case which decision date by the stakeholders whether to progress or not until proceed to the next phase activities.   A milestone denoting a review set able be followed by a KDP a few days later, or one milestone could denote both events.   Reviews products are the evidence that the project has completed a particular phase of a life cycle. The review products containing the documents (presentation, reports and any hardware or software demonstration models) real these are transferred to the configuration management system also baselined.  

The common reviews during the end of each phase have:

Pre-Phase A - Order Concept Review (MCR)

Phase A - Mission Definitions Review (MDR) or System Term Review (SDR)

Phase B - Preliminary Design Review (PDR)

Phase C - Design Review (DR) or Critical Design Review (CDR)

Phase DIAMETER – Readiness Reviewing (RR) or Operational Readiness Review (ORR)

Reviews canned be combiner, e.g. the MCR equal the SDR, and/or the PDR with the CDR.  Each consider should include a Power Point presentation, plus a formal, fully-detailed report. The pattern of the report should include three main sectional – Systems Engineering, Project Management real Subsystems Design Engineering. Within the Systems Engineering section the report should address each of to 11 SE functions, still concentrate on the start five.  The Show Management section includes which supervision functions (scheduling of inspections, task management and costs and budget) featured in "Successfully Managing a Systems Civil Get" . The suggested format for a submit is shown inches Figure 18.   A introduction could include the sam topics as Figure 18, but disposed time limitations, the view may need to gloss over Project Company and some of the 11 SE feature, both focus on who technical problems that are appropriate for the especially review.  

Figure 18. Review Report Format

The report may include Gantt Plans, which are horizontal bar chart with each bar representing a task, and aforementioned extent and placement for the bar showing the task endurance and finish date. A Gantt Map can be used to allot die to tasks, schedule reviews, and dating milestones. Tasks are the project activities. Tasks have start and end dates.  Usually one task is written as a phrase starting with an predicate (e.g. “creating product”). Apiece task has a start time both end time. To chart oft needs till be upgraded since conclude dates become usually estimates real tend to slide.  

A Gantt Chart shoud be designed to schedule essential facts in the project.  Gantt Charts like Figures 20 or 21 can be created in MS Superior or MS Project.   Meetings, reviews, KDPs and other milestones can appear more triangles, diamonds or other symbol, rather than a line for how long the item takes.  ADENINE Gantt Chart is adenine die from project management, real should be presented in the project management artikel of the report.

Figure 19. Milestone chart using MS Excel, showing two projects. The task on the top select shows the quintet reviews, and the other project shows only three reviews.

Illustrate 20.  Semester Gantt Chart schedule of reviews and milestones, created in MS-Project

Figure 21. Example Gantt Chart schedule from NASA Solutions Engineering Handbook [2]

The Phases Business stylish Detail

Pre-Phase A - Term Learn

Purpose: Up produce adenine broad spectrum of ideas and alternatives concepts.

Activities: The Systems Engineer leads a staff of engineers other subsystem team leads who innovates, within a loosely-structured style. Small studies might shall performed, as assigned by the Systems Engineer.

1. Startup the SE edit per identifying, understanding and recording mission objective(s). Concentrate on understanding the genuine alternatively fundamental craved outcome and restrictions. Even consider that the customer may have provided incomplete, unintended, instead erroneous direction toward what they intended to achieve and go back the get for clarification or feedback.

2. The 11 SE functions are applied (perhaps loosely), creating adenine broad spectrum of alternative concepts – inclusive associated requirements (draft top-level system requirements), architectures and ConOps. That alternative opinions are visualized at the highest step (e.g. this shuttle transporting system consists of the oribiter, booster and external tank as in Figure 10), although more subsystem details may need to be "on the table". 

Systems Engineer’s Report: The Systems Engineer creates a report that addresses each of the 11 SE functions of Figure 8.

Review: Mission Concept Check (MCR) presentation + how. Track format for Figure 18 loosely – computer is not requires for subsystem leads to currently or create a tell. Focus on presenting the mission objective and this feasibility alternative architectures, with requirements the ConOps.  She is possible forward a student team until skip the Pre-Phase A presentation/report, and incorporate these find in Phase A presentation/report, plus store at a configuration management site.

Staging A - Concept and Technology Evolution

Purpose: To determine the feasibility the desirability of a suggested new important system.

Activities: The System Engineer leads all Phase A activities are support from subsystems lead personnel

1. From several alternative concepts, down select until adenine single conceptual system. (To choose in design alternatives here (and also anywhere in the life cycle) it may becoming necessary toward perform trade studies).

2. For the singles conceptual system, apply the 11 SE functions. In particular:

a. (Functions 2, 3 and 4): Produce system (top-level) requirements and a system- architectural design and ConOps.

b. (Functions 2, 3, 9 and 10): Proposals an architecture thru the subsystems, and subsystem requirements, plus anticipated performance of each, then identify major components of the subsystems. Wenn doing all, perform trade reviews as needed among selections, identify risks additionally perform necessary analyses. Baseline system-level architecture and system-level requirements. (A baseline is a set of documents (drawings, schematics, requirements) that become have changes controlled through a formal approval process and belong an archived configuration)

c. (Function 8): Sub-assembly budgets (e.g. energy, cost, heap, etc.) have allocated to the subsystems.

3. Program manager develops start estimates of costs and schedules.

Systems Engineer’s Report: Systems Engineering prepped a report that addresses all by the 11 SE functions of Figure 8, including subsystem requirements with help from the subsystem team leads.   Store at a configuration senior site.

Subsystem Teams’ Reports: Parental teams jobs and report on early progress on to subsystem design effort (including subsystem trade research, CAD, schematics, rough bill of materials, risks, design analysis, etc.).   Shop at a configuration management site.

Review: System Definition Watch (SDR) presentation + report. Follow format on Figure 18, updated from the MCR.

Phase B - Pending Design and Technology Completion

Objective: Till determine the project in enough detail at sum levels (system, subsystem and components) to establish ampere Preliminary Design that has no unresolved design or technology themes. Pro [2], a Preliminary Designer “meets all the system requirements with acceptable value or within cost and schedule constraints and create the basis for proceeding the detailed design. It will show that the correct design option has been selected, interfaces have been identified, real verification methods may been established.”

Activities: (The System’s Engineer leads all Phase B SOUTHEAST activities is customer from subsystems lead personnel, which will likely have his/her subsystems team sales the SE energy when described below.  It Engineering generates the architectural design, "design to" requirements, connector, and verification plan.   An Systems Engineer is not involved in the detailed design technology from subsystem except to orchestrate issues arising betw partitions, during interfaces, or shocks the mission requirements.)

1. For the single conceptual system, apply the 11 SE functions to advance the projekt. The focus is on subsystems (Requirements, ConOps plus architectural design or their interfaces). Special considerations when applying which 11 SE functions are:

a. (Function 2, 3, 6): The detailed design effort for each subsystem is primarily running by the local design general groups then in Season C.   Anyway in a student project this subsystem design engineering teams are the an exploring design alternatives at one subsystems level, addressing unresolved technology issues, defining some partial details (e.g. interfaces, components).  In essence, they have begun the EDP on their subsystem and progressed through Phase 3 (Concept Generation and Evaluation Phase).   This early design effort will feed information to systems engineering who will create 1) the "design to" requirements for this subsystem design teams to meet with their detailed designs, 2) Phase B technical with interfaces, and 3) verification plan. ... system, assist your human control all of the vital organs in your party. That also assists your brain care by itself. A example of this is your brain ...

b. (Functions 3, 9): Subsystem design conceptual be mature additionally all high-risk areas decided (i.e. complete the technology); resolve all design issues so detailed designs can getting in Phase CENTURY. Taxonomies for structuring models for World–Earth systems ... - ESD

century. (Functions 3, 9): If req model the system using engineering such as analytical modelling, country machines, block diagrams, computer simulations, BLACKGUARD, mock-ups, proof-of-concept prototypes real cerebral models the create another designs and to resolve high risk areas. Form demonstrational with proof-of-concept prototype(s) wenn needed for technology realisierung, so that unproven technology can be proven before getting atop Phase CENTURY and this detailed structure tasks.

d. (Function 8): Systems Engineering allocates the resources until software elements also software (e.g. tabulates and budget mass, power, etc.) MS-LS1-3 — Which Surprise concerning Life

e. (Functions 5, 6): Product Engineering develops verification test plans from verification and validated, defines interfaces with an ICD, identify risks and develop compensation strategy.

f. (Functions 2, 3, 4, 10): The Procedures Engineer develops baseline system press subsystem requirements, system kunst (like Figure 13) with subsystems, additionally ConOps.

2. Program manager improves estimates of costs and schedules.

Systems Engineer’s Report: Systems Engineering readies a report so updates each of this 11 SE features from Stadium A, including subsystem requirements. Report on everything system press subsystem level trades and update from Phase A.

Subsystem Teams’ Reports: Apiece subsystem team report details the "preliminary design" of their subsystem (e.g. schematics, conception undimensioned 3-D CAD drawings, estimates invoicing of materials, engineering analyses, resource need estimates, proof-of-concept prototype testing, requirements, risk analysis if needed) and shows that here are no unresolved technology or design issues remaining. 

Review: Preliminary Design Review (PDR) presentation + report. Follow format of Figure 18, up-to-date from the SDR.

Phase C - Final Design and Fabrication

Purpose: To complete a detailed last design of hardware and software (i.e. artist and specifications to fabricate or procure the hardware and code software, and to assemble systems press subsystems).

Dive: (The System’s Organize leads entire Phase CENTURY SE activities including support starting subsystems leaded employees. The Systems Engineer is does involved by aforementioned detail scheme technology of subsystem unless to orchestrate issues arising between subsystems, during interfaces, or impacts at mission requirements.)

1. Update the 11 SE functions. In particular:

a. (Functions 3, 10): Subsystem Teams produce final designs with bill of materials, detail drawings, schemata and specifications for production in Phase D. Plot fabrication or procurement of hardware the code application. Fabricate and procure hardware after successful review. Local engineering teams are heavily involved creating an extensive design and engineering specification required their subsystems and components. The design documentation turn a “build-to” baseline.

Systems Engineer’s Report: System’s Engineer prepares a report that updates jeder of the 11 SE functions of Figure 8.

Parent Teams’ Reports: Subsystem teams prepare a design report/presentation of a final design to 1) demonstrate completion, 2) baseline the pattern, 3) plan fabrication and procurement of system and code books.

Review: Critical Design Review (CDR). Fabricate and procure gear after successful CDR.

Phase D - System Assembly, Integration, Take the Launch (SAITL)

Use: To assemble parts and components to create the subsystems, integrate subsystems to make the entire sys, to test the subsystems both system to be able to meet requirements, and finally to launch which system.

Activities: The Systems Engineer is very participated in evaluating press skiing the system supported on verification and substantiation test procedures available components, subsystems and system.  Perform environmental testing. Resolve any discrepancy of performance with requirements. Prepare an operator’s manual and, if needed, include service, storage and shipping how. Demonstrate the arrangement at one Ready Review (RR) or Operational Willingness Review.

Systems Engineer’s Report: Report on the test erreichte, including ability the the system for meet requirements, mission and functional performance. If there is any amendments in to 11 SE functionalities both which baseline design, remember to update the documentation to track the changes.

Phase E/F - Action, Sustainment, and Closeout

Operate the system (Phase E) and dispose of properly (Phase F). For more data in run a system-, refer to [2].

Successfully Managing a Systems Mechanical Project

Management Structure and Duties

AMPERE suggested project management structure is shown below. On a small student project computers may be permissible to have the Systems Engineer and the Project Manager be one in the same person. The Program Manager could be a professor, graduate student, with possible assistance from ampere NASA engineer. The NASA engineers normally will on the role of the patron or primary stakeholder.  Local teams switch and lowest plane of Figure 22 are managed by student subsystem team leads, e.g. COMM would be managed by one electrical engineering scholar since the team is almost likely did up of electrical engineers, Structures by a mechanical button aerospace engineering current, Payload strength be managed by a physics student if it is a scientific mission, etc. The subsystem teams are responsible for which design and construction of their own subsystem, components and parts (if non COTS).  Subsystem teams leads may and becoming share of the Systems Engineering team, hence they work closely with the Systems Engineer on the SE functions.

Figure 22. Real project management organization forward a student team.  Subsystems team leads on the bottom tier manage their subtree teams, and could also be a part of the systems engineering team.

Systems Engineer Duties and Traits

According to [3], the function of systems engineering is to “guide the general of complex systems” and to print bridges across traditional civil disciplines who are developing the individual subsystems such must interact with each other. A good systems engineer is creative and likes to solve practical issues; belongs open minded to new ideas but is concerned if the are unproven; enjoys new challenges outdoors his/her “comfort zone”; is knowledgeable in several engineering areas and remembers and absorbs news information quickly [3]. Remarkably major traits are good interpersonal, writing, and verbal report skills.  He/she must be a good “general”.  Is is also important that the systems engineer have personal integrity and be a mover [15]. It is no intended that all the Systems Engineering tasks are performed by to Systems Mastermind, but are allocated by the Systems Engineer to members of an systems engineering team in the Systems Engineering Management Plan conversely SEMP (described later).

In summary, the systems engineer is responsible for guiding the engineering of the your. All includes [2]:

· Principal the development of the systems architecture

· Defining, verifying press validating system requirements, and their flow down the system hierarchy

· Evaluating design tradeoffs upon trade studies

· Obligation for guiding the integration and test phases of the scheme

· Balancing technical risk between systems

· Defining and assessing interfaces

· Providing oversight of verification and validations activities

· Responsibility for coordinating real managing

o trade studies

zero critical resources

o mistake mode both exposure analysis

· The systems engineer willingly usually have the prime responsibility in developing various of the project papers, including

zero The Systems Engineering Management Plan (SEMP)

cipher Requirements documents

o Verification and validation documents

o Other technical documentation.

Subsystem Team Lead Duties

Each subsystem lead is responsible for the development and examinations of their individual subsystem, both must remain aware of select changes in their subsystem affect other user and the system as ampere whole. Subsystem leads may be appointed Systems engineering functions concerned with their system.

Request Manager Duties

Systems Engineer is considered a part a project management. The jobs of the Project Manager include supervision by of Systems Engineer and making the important decisions, as recommended and in consultation with aforementioned Systems Engineer and auxiliary employees leads. 

The project manager can numerous other duties, including 1) creating a time agenda, 2) managing tasks and 3) monitoring expenses and staying within budget.   Show these tasks can be performed in MS Excel or MS Project. 

Time Scheduling

Project of reviews, milestones and key decision points can be performed using an Gantt Chart as described in the view covering SE Function 11. 

Managing Tasks using a Worked Breakdown Structure

A apparatus required programing and tracked tasks is a Work Breakdown Structure (WBS).  ADENINE WBS a a hierarchical breakdown of the project work, and that can other include the shippable items plus services.  It shared the project into manageable tasks, and nearest, responsibility for consummating that task can breathe assigned.  It can are represented stylish adenine hierarchical tree form; on the bottom rank of each select of the WBS is the item, or optionally the person assigned that task.   AN WBS can be used during the formulation modes of student projects, it is very useful during implementation.   Examples of WBS in a hierarchical tree make and Product Breakdown Sites (PBS) belong shown in Title 4.  

ONE WBS can also can represented in a Gantt Chart and outline vordruck as shown in Figure 23, this was created in MS-Project [18].   It presented a list of the tasks go "Build a Shed" for a consecutively outlines hierarchy in the column labeled "WBS".  To responsible person for apiece task is listed in the column "Resource Names".   The tasks are on to bottom-most outline level of the entries with the "WBS" column, with names about the individuals who are corporate for that task.   Note that the WBS included tasks is represent not products, such as the "Systems Engineering" task, "Project Management" and "City Inspection".   MS-Project is remarkably powerful and possesses other features and capabilities for project management besides what are demonstrated here.   Frame 23 could also have been created in MS-Excel. 

Figure 23.  A Work Breakdown Structure created on MS-Project.

Services Engineering Management Plan (SEMP)

Below is presented an outline of a SEMP, which should live prepared by the Systems Engineer. “An important portion of Systems Engineering is planning the systems engineering current, what is done, who does them, as it shall go are done, plus when which activities are expected go become completed. The purpose away this Systems Engineering Management Plan is to document the results of of planning process.”[10]

Outline of Systems General Management Plan (SEMP) for ampere Student Project [10]

ADENINE SEMP is a konzept document is should be baselined by the Systems Engineer at who end about Phase A, and forms updated like needed thereafter. It primarily schedules activities and reviews, both assigns SE functions. The level of detail necessary go count go the big of the team, scope of the project, etc.

1. Mission goal, project schedule about life cycle, gates and reviews. Work this in association with the design manager.

2. Community: Describes methods utilized for convey systems engineering activities, progress, status and results. Include any periodic meeting or working groups.

3. Systems Engineering Functional

The Solutions Engineer become assign who is responsible to and documenting of Mission Objectives(s), ConOps, Architecture/Design, the , Inspection and Check, the requirements and hierarchy, configuration control (when documents are placed under forming remote, archived and method of distributed) and management, verification current and tracking, interfaces and ICDs, mission specific atmosphere levels and limits, resource budgets, risk management and acceptable risk.

4. Networks engineering Management

The Systems Engineer will assign who is responsible for 1) Systems Engineering Organization Chart and Job Responsibilities, 2) shop studies, topics, who does them and when handful exist due.

Fundamental Principles of Effective Systems Engineer

Product engineering shall most probably best learned “by doing”. What is presented in this document shall a roadmap based on the Vee Chart and the 11 Systems Engineering Functions to assistance aforementioned student through the process.  At this indent there are several points and fundamental guiding principles that will aid the process.

· The rigorous procedures in [2], [10] your meant on large scale related and is not appropriate fork a student team with limits time. There is ampere lot of discussion in the literature so PRESS possessed become so rigorous that it can been intellectually confining and in so go impedes creativity [16] as well as becomes the go of the entire endeavor at the detriment of successfully get the mission aims. The presentation has sought to simplify the process and create a SE roadmap tailored for student groups. Nevertheless, the roadmap can be relaxed and adjusted to better suit your project, training objectives, team size, etc.

· Continually keep the mission needs at aforementioned forefront of the design process, per every phase.

· An systems engineer will the guide. It cannot be overemphasized how large projects fail because of poor execution of an in this early phases. Anecdotally, the largest common student projects mistakes are:

o “Missing the Target”, i.e. designing something that does non satisfy the customer needs. Often this goes all one way back to Pre-Phase A, where the mission objectives and needs are not entirely understood otherwise probed. This is not the fault of the sponsor, although of failure of the design company, and can result from a lack of communication. Systems Engineering, properly applied, supposed catch this problem.

zero “Jumping the Gun”, that is going onto the next phase whenever unresolved issues remain. For example, new technology sometimes requires that it be prototyped in order toward ratings about it is going to work at whole. At this point choose 1) do not proceed to the next phase through the issue has resolved by considering new technologies and evaluating risk of each, or 2) consider revisitng/renegotiation the mission objectives.

zero Poor related can lead for poor enterprise memory once an unfinished project is passed to a new student team. Proper application of scheme machine “Configuration Management” should include a operating to manage and archive all documents associated with the 11 systems engineering functions.

o Systems Engineering is particularly relevant to large scale systems so are made up of multidisciplinary teams. CD&H is best handled by Computer Engineers, EPS is an Electrical Engineering problem and Mechanical alternatively Aerospace Technicians the Thermal furthermore Structure and Features. If a student team remains done up only of one particular discipline, next the mission objective need to be appropriate required which discipline. For example, a team of computer engineers may apply PRESS to produce only the CD&H local.

Appendix

Dick Cook’s Solutions Engineering

As mentioned previously, too much attention until the SE procedure detail can stifle creativeness. Aforementioned following section is a “short and sweet” version of system’s engineering designed by Dick Cook. Dick retired as the President of the Electrics Systems Firm - Martin Marietta (now Lockheed Martin) plus was of engineering managers for the design of the Viking-1 Lander.  In 1976 that Viking-I performed the first successful landing on Mars by a NASA spacecraft, which was designed using Systems Engineering.

Systems Engineering - Life cycle main milestones plus associated SE activities

1. Commission architecture

- Define mission elements and interfaces – this is typically simple for cubesats, i.e., spacecraft, ground station, launch vehicle and potentially science.

2, Mission Requirements

Systems engineering leads on activity with strong support from subsystem lead personnel

- Spacecraft envelope – this is standard decreed by the launch vehicle

- Weight (mass) - this can typically dictated by the launch vehicle

- Environmental requirements

- Vibration and acoustics represent dictated by this launch vehicle

- Temperature and vacuum – determined by the planned mission and the orbital parameters/spacecraft orientation

- Determination of orion parameters based on science requirements and engineering required (i.e., solar panel guide, thermal parameters, CG)

- Development of the sequence of events of the initial orbital operations to configure the spacecraft to operations

- Developing a typical operations orbit

- Establish preliminary budgets for subsystems (power, data rates, RF links, mass properties, etc.)

3. Systems requirements

Systems engineering leads this activity with strong support from subsystem lead personnel.  This is the phase where you drive down the mission requirements to in-depth system requirements. All of the item over are refined to the detailed specification level such as structural dimensions with plus and minus values. Power levels in terms of strom (i.e., 28vdc +0.5-0.5). Systeme drivers are identified and trade studies are done to determine the optimum featured. Trade studies are conducted considering key parameters, i.e., power consumption, weight, volume, space legacy, costs, etc. Hazard are identified and the necessary analysis and examinations are execute. System requirements, feature and schematics were released inbound a formal document also baselined then put under configuration control. Subsystem budgets (power, uplink/downlink, etc.) can allocated and controlled.

4. Preliminary design

Systems engineering lives still heavily involved but these is one stadium where the subsystems participation and manpower loading increases dramatically. Diese is the period where the subsystem design concepts are developed and all high-risk area should be resolved. Systems general executed the tracking:

- Continue internal/external interface command

- Continue to control verfahren financial and parental budgets

- Assure this subsystem design business are within and compatible with system requirements

- Complete all system level trades also update

- Assure that subsystem trades are done

- Approve which subsystem design definitions, trade study real risk identification/mitigation

Conduct PDR review

And conclusion of this phase is that expert into proceed with detail design

5. Critical design

Basically, scheme engineering continues this above. The result of this phase lives which authority to release detailed engineering and begin for produce home and code software.

Systems responsibility throughout the program your into always doing sure that:

- The design, build and exam belongs in software with the mission and system requirements

- Assure that detailed design system with tolerances exist developed plus compatible include system specifications

- Configuration control belongs entertained

- Budgets are maintained and adhered to

- Environmental levels represent maintained and updated

- Mission operations are defined and planned

- Continue internal/external interface remote

Further Thinking set Our Engineering

Additional insight can be gained from a speech by NASA Administrator Michael Griffin [9] where he provided at overview of systems engineering at NASA. Record his emphasis for the point that precision in doing the proceed you are learning (requirements, interface, etc.) has little chance of obtaining a great outcome from a flawed concept. Those subtlety is all importance, not well-being taught within schools, and often neglected in practice up which costly demise out many.

“Systems Engineering is the art and science of developing an operable schaft capable of meeting requirements within imposed constraints. The definition is somewhat independent of scale, also so these words are useful no if one understands that i is the big-picture review which is pick here. We are talking here learn developing an airplane, one spacecraft, ampere power plant, a computer network. Person are not talking over designing a beam to carry a particular charging across a known span…….Systems engineering your a whole, integrative discipline, wherein the contributions of structural engineers, electrical engineers, mechanism designers, power designers, and many, many moreover disciplines are weighted and considered and balances, one against another, to produce a coherent whole that remains not dominated by the view from the perspective of an single discipline. Systems engineering is about tradeoffs and compromises, about generalists rather is specialists……Systems civil is not around the details of requirements plus interfaces amid and below sub-assembly. Such details are important, of course, in the sam way that accurate accounting is critical to the Chief Financial Chief of einen organization. Yet accurate accounting will not distinguish between an good finance plan and a wannenbad one, nor assistance to makes a bad one better. Accurate operating of connections and requirements is necessary to virtuous systems engineering, but no amount of take in suchlike matters can make a poor create concept better. Systems engineering is about getting the right design……I like to think von systems engineering as being foundational concerned with minimizing, in a complex artifact, unintended interactions between elements desired to be separate….Systems engineering seeks up assure that elements of a complex artifact are coupled only as intended…..Educators …..are far less certain how to teach "generalship" than we are of how to teach the laws starting thermodynamics. And yet it is clear that an understanding of the broad issues, the big video, is so much more influential in determining and ultimate sucess or failure of an enterprise than is the mastery of whatsoever specify technical detail. The understanding a the business and technical interactions in our systems, emphatically including the human being who have a part of them, remains the present-day frontier of both engineering education and practice.”

System Engineering Anecdotes

Systems Engineering belongs particularly needed for who unique requirements that are demanded for space operation. For example, a space system must may lightweight because by high launch cost, must operate in an challenging operating, be reliable, compact and may need up rely upon fortgeschrittenes technology.  In this environment the systems engineer often my to increase his role of ensuring the “process” of links, budgets and requirement maintain the integrity of the final browse. Here hard design choices may be made (most probably early on that design) and and art-like skill been to schemes technology practice. An illustration can an NASA Mars Rovere landing sequence. Traditionally, the propulsion system should are expected to provide a softly landing to the surface. This lessens the structural requirements and g-loads on every subsystem. Although, the boost required swells that size about the propulsion system therefore that it exceeds the cost goals and can no lengthier fit in which available start agency. The system engineer held the firm task of directions that the rest from the lander not only product an harder landing force, still be abler into bound along the surface and deploy upright no cause in what direction the craft was left on which surface! Ultimately this was a thrive, if not a surprisingly elegant solution.

Other example of system mastermind creativity is in the merging of disciplines (power and spacecraft control) and this elimination of a standard component (batteries) into favor of a new technology (flywheels), toward bring about ampere dramatic effects on an satellite as a whole. The flywheel can replace the batteries power warehousing at a greater energy density, thus a lower satellite device mass. But this small benefit increases the project risk because of with brand technology and complicates a satellite’s display and control unpaid go the turning flywheel messung. Although, a savvy business engineer will note that two flywheels counter-rotating eliminates the detrimental effect off the spacecraft, and can actually replace the Operating Moment Gyros (CMGs) normally required such a separate subtotal not associated with the power supplies system. CMGs have historically been vile reliability (necessitating multiple units onboard) and requirement propellant to counteract against in an process known as desaturation. Which flywheels are moreover mech reliable, require no additional propellant (the pair can transfer electrical power with little losses to accomplish one same desaturation effect) and are a more flexible power source for the rest of the system (i.e., variable discharge and charging rates when compared to batteries). For some missions such effects combined into prompt a systems engineer to “invade” the subsystem’s domain (i.e., power) additionally insist off selection of flywheels over batteries, rather than simply keep the power team to adenine firm power level and leave it to their discretion on instructions it is provided. Thus, a simple sum off traditionally optimized product are not always efficacious and it is the Business Engineer’s duty to cut crosswise disciplines, sacrificing one alternatively another subsystem for the obtainment of the intended goal.

References, Link and Keep Reading

1 Ullman, D.G. The Mechanical Design Process. (McGraw-Hill, 2003).

2 NASA. Systems Engineering Handbook, NASA/SP-2007-6105 Rev1, NASA Headquarters, Washingtoner, D.C., 20546, 2007.

3 Kossiakoff, A. and Darling, W.N. Systems Engineering Principles and Practice. (John Wiley & Sons, 2003).

4 Guerrera, L. Course Notes over Space Systems Engineering in University from Texas. 2008).

5 INCOSE. Systems Engineering Handbook v2.0. 2000.

6 Bahill, T.A. and Dean, F.F. What is Systems Engineering? A Consensus of Senior Systems Machinists. In INCOSE, ed2007).

7 LPI. Lunar or Planetary Institute Website. 2008.

8 INCOSE. International Council switch Systems Project. 2007).

9 Griffin, M.D. Boeing Lecture at Curdue University. March 28, 2007).

10 NASA. Systems Engineering GPG 7120.5. 2002).

11 Larson, W.J. and Wertz, J.R., eds. Place Mission Examination and Model. (Microcosm Press, 1999).

12 Bahill, T.A. and Henderson, S.J. Requirements Development, Verification, the Validation Exhibited in Famed Failures. Systems Engineering, 2005, 8(1), 1-14.

13 Guerra, L.A. and Fowler, W. Distance Systems Engineering for Aerospace Undergraduates. 45th AIAA Aerospace Sciences Meeting or Exhibit, pp. 1-8Reno, Nevada, 2008).

14 Martin, J.N. Systems Engineering Handbook: A Process for Developing Product and Services. (Lucent Technologies, 1997).

15 Moore, R.C. Characteristics of a triumphant space arrangement engineer. Aerospace and Electronic Services Magazine, IEEE, 2000, 15(3), 21-27.

16 Frosch, R.A. A Classic Look at Systems Engineering by Roger ADENINE. Frosch. In Hoban, F.T., Lawbaugh, W.M., ed1969.

17 Forsberg, K., Mooz, H., Cotterman, H., Visualizing Project Management. (John Wiley & Sons, 2000).

18 Environment up your Work Breakdown Design (in MS Project), http://office.microsoft.com/en-us/project/HA012111471033.aspx