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Big ideas are engineered: a resource for schools
page 1
Big ideas BAE Systems Engineering Resource Pack
Big ideas are engineeredA resource for schools
Big ideas are engineered: a resource for schools
page 2
2150 N. 107th St., Suite 205 •
Seattle, WA 98133-9009 (USA)
Phone: (206) 361-6607 or (800)
366-1164 • FAX: (206) 367-
8777
Email: [email protected]
World Wide Web URL
http://www.incose.org
To: Teachers reading the “Big Ideas: BAE Systems Engineering Resource Pack’’
8 July 2005
Dear colleague:
SYSTEMS ENGINEERING CASE STUDIES FOR SCHOOLS
The International Council on Systems Engineering (INCOSE) is delighted that BAE Systemshas taken the step of making these case studies available, in order to raise awareness ofsystems engineering amongst young people in schools. It is important that young people, andcrucially their teachers, are helped to understand more fully how systems thinking andsystems engineering impacts upon everyday life. We would encourage you, their teachers, tomake use of the resource in the classroom and hope that it will inspire more young people topursue careers in engineering, and systems engineering in particular!
Yours sincerely
Professor Heinz Stoewer Paul RobitaillePresident President ElectINCOSE INCOSE
INCOSE BOARD
PresidentProf. Dipl.-Ing. Heinz Stoewer, M.ScSpace Associates GmbH
President-ElectPaul RobitailleLockheed Martin
SecretaryWilliam D. MillerStevens Institute of Technology
TreasurerPat HaleSysteMentor LLC
DIRECTORSBill EwaldORC Macro InternationalDirector for Strategic Presence
David LongVitech CorporationDirector for Communications
Donna RhodesM.I.T.Director for Strategic Planning
Christopher DeanDirector for International Growth
Corporate Advisory BoardDave WaldenGeneral Dynamics
Member BoardBruce SheltonANSER Inc.
Ralph Hill, IIIGolder Associates, Inc.
TECHNICAL DIRECTORSamantha BrownBAE Systems
DIRECTOR FOR COMMERCIAL OUTREACHJohn QuitterXerox
Managing ExecutiveShirley Bishop
Big ideas are engineered: a resource for schools
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At BAE Systems
Richard HamerEducation Partnerships Director BAE [email protected]
Project co-ordinators
David BarlexNuffield Curriculum Centre
Torben SteegSystems and Control consultant
Desk Top publishing
Jo OladejoNuffield Curriculum Centre
Design concepts
Dave Mackerelldevised
Participating Schools
Broadlands SchoolBristol
City of Portsmouth Boys SchoolPortsmouth
Devonport High School for BoysPlymouth
Westcliffe Girls High SchoolWestcliffe-on-Sea
Acknowledgements page
Carr Hill High SchoolPreston
Lytham St Annes High Technology CollegeLytham St Annes
The following individuals made a significant contribution to these materials
David James Educational ConsultantAndy Hughes Segway HT advisorAmanda Pearce Loughborough UniversityAllan Seabridge BAE SystemsRussell Davison Losing power case studyMichael Dean Losing power case studyRobert Eato Losing power case studyBen Foster Losing power case studyRichard Gould Losing power case studyMichael Hartley Losing power case study
Big ideas are engineered: a resource for schools
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1.0 Introduction Page 5
2.00 Systems Teaching2.01 Systems Thinking concepts Page 62.02 Using WJEC D&T GCSE in Systems and Control for systems engineering Page 16
3.00 Engineering the links between design & technology, maths and science3.01 An audit approach to developing links between maths, science and D&T Page 193.02 Creating a systems engineering designing and making assignment Page 213.03 Feedback sheets Page 23
4.00 Systems Engineering Case Studies4.01 Introduction Page 314.02 Using the studies Page 324.03 Systems in the gym Page 344.04 HybriDriveTM Page 404.05 Segway (i) Page 484.05 Segway (ii) Page 564.05 Vehicle Management System Page 644.07 Power out in USA and Canada 2003 Page 724.08 Feedback sheet Page 80
Contents page
Big ideas are engineered: a resource for schools
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Big idea 02: Successful design
The aim of the Big Ideas resource is toprovide you with a set of resources andapproaches that will enable you and yourpupils to use systems thinking to enhance thedesign & technology curriculum, to provide anappreciation of the work of systems engineersand develop an appetite for pursuing atechnical career involving systems engineer-ing.
The pack has three main sections.
• First, there is “Systems teaching”.This provides a detailed treatment of theideas needed for teaching a systems ap-proach and how the Welsh Joint EducationCommittee GCSE Design & Technology inSystems and Control can be taught using asystems engineering approach. There is afeedback section to allow you to ask the authorquestions about systems teaching and thinking.
• Second, there is “Engineering the linksbetween design & technology, mathematicsand science”.This requires innovative curriculum develop-ment particularly as since the introduction ofthe National Curriculum these subjects havepursued their own teaching with littlereference to each other. Systems engineer-ing demands the use of knowledge, under-standing and skill from a wide range ofsubjects and beginning with developing linksbetween these three subjects is a good wayto start. There is a feedback section to letthe authors know about the projects you areusing to build links
• Third, there is “Systems EngineeringCase Studies” to introduce pupils to theworld of systems engineering and provideinsight into the impact of systems thinking.There is a feedback section so that you can
let the authors know how you are using thestudies and how they might be improved.
BAE Systems Engineering and the authorshope that you and your pupils will enjoy usingthis resource pack. It is available as a singleunit or single elements on the BAE SystemsEngineering website at www.baesystems.com/education/systemsengineering.
Welcome to Big Ideas, the BAE Systems Engineering Resource Pack.
For further information about how to usethis pack you should refer to p32.
Big ideas are engineered: a resource for schools
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Systems Thinking Concepts
IntroductionSystems ideas as a tool for supportingpupils’ thinking about a wide range ofsituations in Design and Technology (D&T) arenow well established in the UK NationalCurriculum, in exam specifications and inschool texts. In particular they have proved tobe powerful in helping pupils from Key Stage2 onwards design and make in the area ofcontrol and, in particular, electronics. This isbecause a systems based approach allowspupils to fully engage in design work in theseareas by suppressing technical complexitywhile bringing to the surface those featuresof the design context that are within pupils’grasp.
Systems thinking is used in D&T in a varietyof ways; to support high level approaches tocomplex situations when pupils are designingand making control systems, to help pupilsanalyse and describe the designs of others,for example in product analysis activities, andas a descriptive tool when pupils need to
understand the operation of complex entitiessuch as a manufacturing system or someelement of an eco-system. It is noteworthythat systems thinking is also used in scienceeducation (especially the biological sciences),in ICT to support the teaching ofprogramming and in the humanities as anexplanatory tool when dealing with complexentities (for example trade relationships).
At the heart of systems thinking are systemdiagrams used to illustrate the key elementsof a system and the relationships betweenthese elements. The development of systemsthinking started about a hundred years agoand in that time a wide range of diagram-matic tools has been developed to supportthinking in a wide range of contexts frombiology to control engineering to describinghow businesses work. In secondary D&Teducation, just two types of system diagramare in common use: block diagrams derivedfrom control theory and flow diagrams, oftenbased on those used in software
development. There is, however, evidencefrom examinations, books and observation ofwork in lessons that the understandings anduses of both kinds of system diagram arediverse and, often, confused both with eachother and other types of system diagram.Pupils can be helped to achieve clarity aboutthe uses of these two kinds of system
diagram if they are encouraged to think aboutwhat the blocks and lines in the diagrams aresupposed to represent.
FlowchartsFlowcharts are generally used to definesequences of instructions; in D&T this isgenerally either in the context of computercontrol programming or to describe a pupil’s(or an industrial) manufacturing sequence.
In a flowchart the various blocks representactions or operations that are to be carriedout with different block shapes representingdifferent types of operation. For examplediamond-shaped decision boxes are usedwhere there is a choice about the sequenceof actions. The arrowed lines simply show thesequence of execution of these operations.
So, flow charts are about events and thesequence in which events should be carriedout. When using them the design questionfocuses on “what does the control systemFigure 1 A flowchart for a simple plant
watering system
▼
▼
▼ Start
Turn on
Yes
▲ Turn offNo
▼
Does thesoil needwatering?
Big ideas are engineered: a resource for schools
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research:
r
need to do next?”.
Block DiagramsThe second type of diagram frequently met inD&T is often simply called a ‘systemdiagram’, despite the broad range of suchdiagrams that exist; for clarity these will becalled ‘block diagrams’ here. These diagramsuse arrowed lines to show signals thattransfer information between blocks whosepurpose is to operate in some way on thesesignals. These are commonly used todescribe the functional operation (as op-posed to the physical construction) of a rangeof control systems including electronic andmechanical systems.
SignalsEach arrow in a block diagram represents asignal. Any physical variable (e.g. light,voltage, sound, force, height etc.) can berepresented as a signal that will have ameasurable value.
A control system will detect one or moresignals at its input and produce one or moresignals at its output. The block diagramshows the route of the signal(s) into, throughand out of the system.
Signals are either analogue or digital:An analogue signal can have any value
(between upper and lower limits). Forexample the level of light, sound andtemperature where you are now are allanalogue signals; they are constantly varying.
A digital signal has fixed values. In mostwork that pupils do just two fixed values areallowed.
For example a doorbell switch may be eitherpressed or not pressed. The temperature iseither less than 20°C or its 20°C or above.
Within digital electronic systems (includingdigital computers) all the signals are digital,the two possible values are labelled as high(or ‘1’) and low (or ’0’). Combinations ofdigital signals are used to provide codes thatrepresent a wide range of things fromapproximations to an analogue value to analphabet character or the colour of a dot on acomputer monitor.
FunctionsEach block in a block diagram represents afunction that affects a signal, for example by:• Changing the type of signal.• Changing the signal’s size.• Combining signals.
The three blocks in the ‘standard’ diagram tothe left represent the three kinds of blockthat exist.
An input block takes signals from theenvironment and turns this information into auseful form for the system; for example in anelectronic system this will be an electronicsignal.
An output block turns systems signals (e.g.an electronic signal) into a signal that is sentout into the environment, such as motion,sound or light.
▲
Outputsignal
Electronicsignal
Electronicsignal
Feedback
Inputsignal
Inputblock
Control orProcess
Outputblock
▲ ▲
▲
Figure 2 A block diagram
▲
Big ideas are engineered: a resource for schools
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A process block operates on signals withinthe system for example combining, timingcounting etc.
The function of a block is always well defined,so that the operation of the control system ispredictable.
Using block diagramsAs with all design tools, block diagrams geteasier to use the more you practice withthem. There are some practical issues toconsider when incorporating their use intowork with pupils:
• Block diagrams can be used to design and describe all types of control system; including computer, electrical,
pneumatic, hydraulic and mechanicalcontrol.
• A block diagram should have bothinput and output signal arrows. Theseare often omitted in textbooks, which
is a mistake that can only lead toconfusion. A system with no input andoutput output arrows suggests asystem with no information entering orleaving it; it is difficult to imagine ause for such a system.
• Power supplies and interfaces are notshown on block diagrams. Thesethings may be necessary for the finaloperation of the system, but they don’toperate on signals directly. A systemdiagram is a way of describing how asystem should work – what itshould do. It will not necessarilydescribe how the desired systemshould be implemented; a blockdiagram indicating a particular functioncould often be implemented in rangeof control technologies.
• For similar reasons drivers such astransistors and Darlington pairs (usedto amplify the current to power hungry
output devices) don’t need to appearon a system diagram. From a signalpoint of view these components haveno effect on the system, though theyare clearly required to allow manyoutput devices to work.
• You do not always have to have oneeach of the blocks shown in the‘standard’ input-process-outputdiagram. In a complex system you
will probably have multiple inputs andoutputs as well as a series of processingsteps. In a simple mechanical system theremay be no sensible ‘process’ block at all. Foran example look at the diagram for a bikebrake system.
A mistake in many school text books is to tryto force every system into the 3 block model,ignoring the fact that these are generic blocktypes.
Large force
(on wheel)
Increases size andchanges directionof force
▲
InputBrakehandle(a lever)
OutputBrakecontrol(a lever)
Force transmittedvia brakecable
Increases size andchanges directionof force
▲Small force
(fromhand)
System Boundary
▲ Figure 3 A block diagram of a bike braking system
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BoundariesDrawing an imaginary boundary around yoursystem will help you see what you need toinclude in the diagram.
For example, in the diagram for a bike brakesystem, the bike rider and the wheel have notbeen included as a part of the system (norhas the road surface or the presence of othertraffic); the system boundary has been drawnto just describe the mechanical brakingsystem.
In a different design situation you might wantto either:
• Draw a tighter boundary. For example,to focus on just one part of thesystem such as the brake handle.
• Draw a looser boundary. For example,you might want to include the cyclistas a part of the total braking feedbacksystem or you might want to consider
the effect of the road on the wheel.
Designing with Block DiagramsWhen designing with bock diagrams, thedesign question focuses on “what needs tohappen to the signal next?”.
Start by asking what signals the controlsystem will need to detect and to produce.“What kinds of physical signal are going intothe computer?”
Each input signal you wish to detect will needan input block in the system diagram and theassociated input signal arrow. When design-ing an electronic system, each input blockrepresents a single sensor that changes aphysical signal from the environment into anelectronic signal.“What kinds of physical signal are going to beproduced by the computer?”Each output signal you wish to produce willneed an output block in the system diagramand the associated output signal arrow. When
designing an electronic system, each outputblock represents a device that changes anelectronic signal produced by the system intoa signal sent out into the environment.
Next, ask what the system needs to do to theinput signal to achieve the desired outputsignal. This where the hard design thinkingtakes place. Often it is useful to start with avery broad description of the desired functionof the system and then gradually break this
Tilt or
tremble
Sound
? ? ?▼ ▼▼ ▼
Electronicsignal
Electronicsignal
Figure 4 Designing a bike alarm; step 1
down into subsystem elements.
Designing a bike alarmFor example, in designing a tamper alarm fora bicycle, you might quite quickly decide thatyou need to detect motion of some kind andthat you want to produce a loud noise:
Big ideas are engineered: a resource for schools
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After some research into possible motionsensors and ways to produce a loud sound,you might settle on a tilt sensor and a siren:
system; a careful thief could take the bikewithout making much sound. The moresophisticated control options available arewide. The siren could stay on once thesensor is triggered, it could stay on for afixed time, it could pulse on and off (eithercontinuously or for a fixed time), and so on.See Figure 7 for a final block diagram,describing a system where the siren islatched (to stay on once the sensor istriggered).
Having defined the system operation thedesigner then needs to decide on an
appropriate technology of realisation. Thiscould be via hard wired electronics, aprogrammable system (for example a PIC) or,in some situations, other control technologiessuch as pneumatics or mechanisms.
Describing Control SystemsThere are two broad types of control system:
• Continuous control systems,• Sequential control systems.
Continuous ControlIn many control systems, the input signal isbeing continuously monitored and the output
▼ ▼▼ ▼
Tilt or
tremble
Sound
Electronicsignal
Electronicsignal
Tiltsensor
? Siren
▼ ▼
Tilt or
tremble
Sound
Electronicsignal
Tiltsensor
Siren ▼
This is however not a very sophisticated
▼▼ ▼▼
Tilt or
tremble
Electronicsignal
Electronicsignal
Tiltsensor
Latch Siren
Figure 7 Designing a bike alarm; step 4
Figure 5 Designing a bike alarm; step 2
How to control the siren based on the signalfrom the tilt sensor is a critical system designquestion. The system could simply cause thesiren to come on whenever the tilt switch isactivated:
Figure 6 Designing a bike alarm; step 3
Big ideas are engineered: a resource for schools
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Red Amber Green Delay
Step 1 On Off Off 60 seconds
Step 2 On On Off 10 seconds
Step 3 Off Off On 60 seconds
Step 4 Off On Off 10 secondsBack to step 1
signal is being continuously controlled.
For example the bicycle alarm could have apressure sensitive switch in the saddle; ifsomeone sits on the saddle when the alarmis enabled a loud siren would be set off.
You might arrange things so that the sirencontinues for a while even if the thief got offthe saddle again. A process block called adelay provides this function; when theelectronic signal going into the delay goeshigh, the signal out of the delay goes high aswell and remains high for a fixed time afterthe signal into the delay goes low.
A block diagram for such a system is shownabove in Figure 8. The signals in this systemare continuously active, even when it appearsto be doing nothing:
• The amount of pressure has acontinuous influence on the signalbetween the sensor and the delay.
• The electronic signal from thesensor has a continuous influenceon the signal out of the delay.
• The electronic signal from the delayhas a continuous influence on the
level of sound made by the siren.
Systems like this are called continuouscontrol systems and are easy to describeusing block diagrams.
Sequential ControlSome systems don’t work in the same wayas the bike alarm. Instead of continuouslymonitoring what is happening and reacting,they simply carry out a fixed sequence of
operations that are separated by fixeddelays.
A very common example of this is a set oftraffic lights. Once the lights are switchedon, the sequence of lights simply repeatsconstantly. At each step in the sequence thepattern of lights changes, with a set delaybetween each step.
Systems like this are called sequential
▼
Sound
▼ ▼▼
Pressure
on thesaddle
Electronicsignal
Electronicsignal
Pressuresensor
Delay Siren
Figure 8 Another bike alarm
Figure 9 State table
Big ideas are engineered: a resource for schools
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Moisturesensor
Dampnessmeasurement
Waterpump
Electronicsignal
Electronicsignal
System boundary
▼ ▼▼ ▼
▼
▼
▼
Water
flow
Moisture in
the soil
control systems and are particularly easy todescribe use flowcharts or state tables.
Many control systems actually have a mixtureof sequential and continuous parts. Forexample a pedestrian crossing often uses aset of traffic lights that only stop the trafficwhen a pedestrian presses a ‘Stop’ button.
• The part of the control system thatis monitoring the ‘Stop’ button iscontinuous.
• The part of the system that controlsthe fixed steps that occur when thetraffic is stopped is sequential.
FeedbackControl systems often need to do more thansimply sense their environment; they mayalso need information on the effect they arehaving.
For example you might design a system to
water your plants automatically.
One way to do this would be to calculate thedaily water requirement. You could thenarrange for this amount of water to bepumped into the soil each day. However, thissystem might not be very effective; in veryhot weather more water would beused and the plant could still dry out. Or youmight swamp the plants in cold weather.
It would be much better to actually sense howdamp the soil is and only water it when dry.The system diagram for such a system isshown below. The thing to notice about thisdiagram is that the signal produced at theoutput of the control system is fed back toeffect the signal at the input of the controlsystem. This is called feedback.
The feedback signal is not an electronic
signal in this example; it is the level ofmoisture in the soil. As water is pumped intothe soil (the output of the system), themoisture level increases (the input to thesystem). However, when you are designingthe system you don’t need to concernyourself with this process or include the soilin the diagram because it is outside thesystem boundary.
Most control systems, apart from thesimplest, make use of feedback and canmonitor the effect they are having on theenvironment they control.
These notes, so far, have concentrated onthe use of systems in the KS3 and KS4national curriculum. Beyond secondaryeducation the concept of what a system isbroadens out considerably and there arelessons that D&T education can learn fromthis.
In its fullest sense, a system is an assemblyFigure 10: A plant watering system
Big ideas are engineered: a resource for schools
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or collection of different elements thattogether produce results that the elementsalone couldn’t achieve. These elements caninclude people, hardware, software, facilities,policies, and documents.
Systems Engineering works at this broadsystems level to not only create products butalso the process for producing theproduct, as follows:
State the problemInvestigate alternativesModel the systemIntegrateLaunch the systemAssess performanceRe-evaluate
These functions can be summarized with theacronym SIMILAR. This Systems EngineeringProcess is shown below. It is important tonote that the Systems Engineering Process isnot sequential. The functions are performed
in a parallel and iterative manner.
State the problemThe problem statement starts with adescription of the top-level functions that thesystem must perform this will includemandatory requirements (that must be met)and preference requirements that may betraded-off to find the preferred alternatives.The problem statement will be in terms ofwhat must be done, not how to do it.
Investigate AlternativesAlternative designs are created and areevaluated based on performance, schedule,
cost and risk. No design is likely to be beston all aspects and systems engineers use arange of analytic techniques to find thepreferred alternatives. This analysis isrepeated whenever more data is available.For example an initial analysis will be basedon estimates by the design engineers.Following this models (both physical andelectronic) and prototypes will be constructedand evaluated. Tests will also be run on thefinal system.
Model the systemModels are developed for most alternativedesigns. The model for the preferred
Systems Engineering
Figure 11 The SIMILAR process
State the Investigate Model the Integrate Launch Assessproblem alternatives system the system Performance
Re-evaluate Re-evaluate Re-evaluate Re-evaluate Re-evaluate Re-evaluate
▼
Customerneeds
▲ ▼ ▼▼ ▼▼ ▲ ▲▲▲▲
▲
▲▲▲▲▲▲▲
▲
Outputs
alternative will be expanded and used to helpmanage the system throughout its entire lifecycle. Many types of system models are used,such as physical analogues, analytic equa-tions, state machines, block diagrams,functional flow diagrams, object-orientedmodels, computer simulations and mentalmodels. As already noted, Systems Engineer-ing is responsible for creating a product andalso a process for producing it. So, modelsshould be constructed for both the productand the process. Process models allowengineers to, for example, study schedulingchanges and perform sensitivity analyses toshow the effects of delaying or accelerating
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certain subprojects. Running the processmodels reveals bottlenecks and fragmentedactivities reduces cost and exposes duplica-tion of effort. Product models help explain thesystem. These models are also used intradeoff studies and risk management.
As noted, the Systems Engineering Process isnot sequential, it is parallel and iterative; asan example of this models must be createdbefore alternatives can be investigated.
IntegrateSystems, businesses and people must beintegrated so that they interact effectivelywith one another. The way that subsystemsinteract must be designed. For examplesubsystems are usually defined along naturalboundaries but also defined to minimize theamount of information to be exchangedbetween them. Feedback loops aroundindividual subsystems are easier to managethan feedback loops around interconnectedsubsystems. Processes of co-evolving
systems also need to be integrated.
Launch the systemLaunching the system means running thesystem and producing outputs. In amanufacturing environment this might meanbuying commercial off the shelf hardware orsoftware, or it might mean actually makingthings. Launching the system means allowingthe system do what it was intended to do.This also includes the system engineering ofdeploying multi-site, multi-cultural systems.
This is the phase where the preferredalternative is designed in detail. The partsare built or bought and integrated and testedat various levels leading to the certifiedproduct. In designing and producing theproduct, due consideration is given to itsinterfaces with operators (humans, who willneed to be trained) and other systems withwhich the product will interface. In someinstances, this will cause interfaced systemsto co-evolve. The process of designing and
producing the system is iterative as newknowledge developed along the way cancause a re-consideration and modification ofearlier steps.
The systems engineers’ products include arequirements document including routes forverification and validation, a description offunctions and objects, a test plan, a drawingof system boundaries, an interface controldocument, a listing of deliverables, models, asensitivity analysis, a tradeoff study, a riskanalysis, a life cycle analysis and adescription of the physical architecture.
The requirements should be validated (are webuilding the right system?) and verified (arewe building the system right?).
Assess performanceTechnical performance measures are used tomitigate risk during design and manufactur-ing. Data (including customer satisfactioncomments, productivity, number of problem
reports, or whatever is critical) are used tohelp manage a company’s processes.Measurement is the key. If you cannotmeasure it, you cannot control it. If youcannot control it, you cannot improve it.Important resources such as weight, volume,price, communications bandwidth and powerconsumption should be managed. Eachsubsystem is allocated a portion of the totalbudget and the project manger is allocated areserve. These resource budgets aremanaged throughout the system life cycle.
Re-evaluateRe-evaluate is arguably the most importantof these functions. For a century, engineershave used feedback to help control systemsand improve performance. It is one of themost fundamental engineering tools. Re-evaluation should be a continual processwith many parallel loops. Re-evaluate meansobserving outputs and using this informationto modify the system, the inputs, the productor the process. Figure 11 on page 13
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summarizes the Systems EngineeringProcess. This figure clearly shows thedistributed nature of the Re-evaluate functionin the feedback loops. However, all of theseloops will not always be used. The particularloops that are used depend on the particularproblem being solved.
SummaryMost systems engineers accept the followingbasic core concepts:
1. Understand as much of the problemas possible before you try to solve it
2. Translate the problem into measurablerequirements.
3. Examine all feasible alternativesbefore selecting a solution.
4. Make sure you consider the totalsystem life cycle. The birth to deathconcept extends to maintenance,
replacement and decommission. Ifthese are not considered in theother tasks, major life cycle costscan be ignored.
5. Make sure to test the total systembefore delivering it.
6. Document everything.
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Using WJEC D&T GCSE in Systems and control for systems engineering
WJEC have agreed that they will be happy toaccept collaborative projects based aroundthe principles of Systems Engineering frompupils following their D&T: Systems andControl specification.
This means developing collaborativecoursework projects based in D&T that alsotap into expertise in the Maths and Sciencecurricula.
Developing collaboration in Design &TechnologyAn essential requirement of developing asystems engineering approach to design &technology is that the designing and makingassignments tackled are too demanding for asingle student. Success necessitatescollaboration. Patricia Murphy of the OpenUniversity has made extensive observationsof collaborative problem solving in the design& technology classroom. Through herresearch she has identified a set of optimalpreconditions for success. These provide
schools with a powerful framework with whichto develop and evaluate systems engineeringbased work:
Teachers need to be committed to support learningthrough collaboration and should understandcollaboration as a learning mechanism.
The task context should set the conditions forjoint decision making during design andconstruction. Critical elements are:
• An explicit negotiated purpose to thetask, linked to individual learning and agenuine need or function to the world;
• Student autonomy and participationin decision making during design andproblem solving
• A shareable task. There should beopportunities for making thinkingprocesses explicit and developing shared
meaning through verbal and physicalinteractions.
• School and classroom organisationthat supports small groups (includingenough time to do so, consistencybetween classrooms in fosteringcollaborations, and reinforcement of thevalue of collaboration through evidence ofteacher collaboration).
A range of pedagogic strategies should beused to support collaboration including:
• Knowing how to select appropriate tasks,i.e. tasks whose demands are withinindividuals capabilities but whichchallenge them to develop and refinesolutions of increasing sophistication;
• Knowing how to scaffold students’problem solving through offering bothideas and tools to make students’
thinking explicit to themselves and others;
• Having the means to recognise and makeexplicit alternative perceptions of salienceand valuing these through discussion andreflection between peers and betweenpeers and teachers;
• Monitoring individual understandings assolutions evolve over time and helpingstudents to reflect on their thinking andthe sources of changes in it;
• Addressing dissonance within groups tothe benefit of all individuals and as part ofthis recognising when collaboration is nolonger constructive etc., modellingways to resolve negotiations;
• Monitoring individual engagement withgroup activity in terms of bothestablishing and enhancing sharedreference points;
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• Maintaining students’ focus on productiveproblem-solving paths;
• Encouraging discussion of decisions.This should include both students andteachers justifying their suggestions foraction. It is important that the studentsretain ownership of the decision makingprocess. To achieve this it might benecessary for the teacher to allowstudents to follow a decision path withwhich the teacher disagrees. In suchcases the teacher should present herreasons for disagreement but allow thestudents responsibility and autonomy.
• Developing an ethos where learningfrom feedback is a continuing processthroughout the stages of activity ratherthan seeing activity as enactment of aclosed solution. A consequence of this isthat products may not be achieved or whatconstitutes a product may need re-conceptualising. The emphasis should be
on the learning achieved, not theproduct outcome.
Students need:
• a shared frame of reference regarding thetask, its purpose and the expectedoutcome (or the opportunity to negotiatethese once individual perceptions aredeveloped to some extent; these mustthen be common or negotiable and thegoals of individuals’ separate tasks needto overlap) personal authenticity andinvestment in outcome (authenticity isindividually constructed and enablesstudent engagement and participation inthe activity);
• appropriate social skills and cognitivestrategies to support collaboration(especially willingness to communicate andco-operate in the activity and to engage inshared decision making; encouraging andvaluing partners’ contributions negotiating
about alternatives, critical evaluation).
In her work Patricia makes the importantdistinction between learning to collaborateand collaborating to learn. Where teacherslack an understanding of collaboration as alearning mechanism they will be unable tosupport pupils working in this way. Central tothis understanding is realising that pupilsneed some social skills and cognitivestrategies for collaboration.
It is important that the teacher models thesort of behaviour required from students.Listening carefully to students and comment-ing constructively on what they have saidpays big dividends. It encourages thestudents to listen to each other and take intoaccount what has been said in planning nextsteps. If the teacher does not do this it isunlikely that the students will develop thesocial skills and cognitive strategies forcollaborative learning and powerful opportu-nities for learning will be lost.
Through her work Patricia has observed anddescribed the work of teachers who didunderstand the nature of collaboration forlearning and had a pedagogic style thatsupported this. As a result the students notonly enjoyed the opportunity to work togetherbut also understood the cognitive benefitsthat accrued from it.
This identification of the factors important inenabling collaboration to take place in thedesign & technology classroom firstappeared in the International Journal ofDesign & Technology Education Journal(Volume 11, No. 3, 2001). In particularPatricia noted that it was the teacher’s viewsof the learner that were crucial in enabling theteacher to appreciate potential for collabora-tive learning. Teachers who view learners aspassive in the learning process, simply asreceivers of information ‘delivered’ by theteacher, are unlikely to see the benefits ofcollaborative learning or of adopting apedagogy that will support it.
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The challenge for schools wishing to adopt aSystems Engineering approach is to use thework of Patricia Murphy and her colleagues toensure the student is viewed as an activeparticipant in the learning process and thatthe conditions for fruitful collaboration aremet in their classrooms. A major part of thischallenge will be developing course worktasks that meet the criteria of the ExaminingBody and have contexts the set theconditions for joint decision making duringdesign and construction.
Groupwork guidelinesSuitable criteria for establishing a groupbased designing and making assignmentmight include:
• the designing and making task is toodemanding for a single individual;Provide clear guidance on matching thenumber of students in a group to thedemand of the project.
• pupils sign up to group work coursework and its implications at thebeginning of major coursework;
• each student has to produce their own‘evidence portfolio’ in which it is clearwhat is their own work, the work of othersand the group’s work;
• each candidate has to contributesignificantly to both the designingand the making of the final product(s);
The group is responsible for monitoring itsown group performance using given criteriaand individuals should comment on this in theportfolio.
The teacher should also monitor groupperformance using the same given criteriaand comment on this; grades are awarded onquality of designing and making.
The best collaborations tend to have the
following structure:
• an initial, ill-defined stage, where thestudents debate ideas and approaches asa whole team.
Followed by,
• a gradual transition to a clearer planand some subdivision of responsibilities,but still a lot of general discussions. Oftenat this stage students will do some of thesub-tasks in pairs,
• in the later stages of the project, more ofeach student’s time would involve workingon their own sub-tasks, but there wouldstill be regular reporting back to the entireteam and discussion, and also some workwould still be in pairs e.g. one studentdoing work and a second student checkingit.
Suitable tasks include any multi-part
communication system (candidates can workindividually on the parts, still having to takeinto account such things as agreed signallingprotocols, agreed product form and styleetc.).
In fact any decent scale electronics projectshould be suitable for collaborative work. Themain criterion is that the work needs to beable to be split up. Electronics basedspecifications are so good for group workbecause systems can be split into sub-systems, subroutines etc.
A possible problem area is manufacturing,because only one person can work on a PCB,or product moulding etc. at a time (butsubsystems could in some cases, legiti-mately from a product design perspective, bemanufactured on separate PCBs with anagreed protocol for connecting the PCBs).
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An audit approach to establishing links between design &technology, maths and science
Developing cross curricula links betweendesign & technology and other subjects is notan easy task but the following four stepapproach provides a straightforward way ofbeginning the task. To begin with the teachersof design & technology must ensure that thecurriculum they teach is robust.
A robust curriculum will have designing at itscore and involve pupils in making designdecisions for themselves. Teachers willorchestrate the number and complexity of thedesign decisions that their pupils have tomake in carrying out a design and makeactivity in order to ensure that theassignment is appropriately challengingwithout being daunting and requires pupils touse particular parts of the design &technology programme of study.
Step 1 Auditing a single designing andmaking assignmentAn important first step in developing adesigning and making assignment is to audit
the range of design decisions that are likelyto be made by pupils tackling theassignment.
This audit can be carried out using five keyareas of design decision: conceptual (overallpurpose of the design, the sort of productthat it will be), technical (how the design willwork), aesthetic (what the design will looklike), constructional (how the design will beput together) and marketing (who the designis for, where it will be used, how it will besold). This can be represented visually witheach feature at a corner of pentagon andeach area of design decision connected toeach other area.
This inter-connectedness is an importantfeature of design decisions. A change ofdecision within one area will affect some ifnot all of design decisions that are madewithin the others.
For example if the way a design is to work is
changed this will almost certainly affect whatthe design looks like and how it isconstructed. It may also have far reachingeffects in changing some of the purposesthat the design can meet and whomight be able to use it.
Step 2 Auditing a sequence ofdesigning and makingassignments
For step 2 this audit is carried outacross all the designing and makingassignments tackled by pupilsacross a key stage. This gives anoverview of the designing that istaking place and if and area ofdesign decision is missing,under-represented or over-represented the nature of theassignment can be adjustedaccordingly.
ConceptualWhat it does
AestheticsWhat it lookslike
MarketingWho is itfor
ConstructionalHow it fitstogether
TechnicalHow itworks
Figure 12 A representation of design decisionsin a designing and making assignment
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Step 3 Identifying design decisions thatcould use maths and science
Step 3 involves looking at each area ofdesign decision made in a designing andmaking assignment and asking two simplequestions. What mathematics can pupils useto inform and improve these designdecisions? What science can pupils use toinform and improve these design decision?
In many cases the use of maths or sciencewill not be particularly useful in which casethere is no cross curricula link. However in afew cases the use of maths or science willconsiderably enhance the quality of designdecisions made. It is here that efforts shouldbe made to establish the links.
Step 4 Important conversationsStep 4 involves talking to colleagues in mathsand science departments about the results ofyour audit. Almost certainly they will belooking for ways to make their subjects useful
through ‘real world’ application and the linksyou have discovered will provide them withopportunities to do this.
Of course there is still the tricky business oforganising the lessons in the differentsubjects so that these potential links can bemade effective but the four-step approachhas identified areas of cross curricula workwhere this is likely to pay considerabledividends to the benefit of all the subjectsinvolved.
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The links with maths and science that youidentify through the audit approach willenable you to develop a culture in yourclassroom where your pupils expect to usemaths and science to enhance their design &technology.
This is an important first step on the path tosystems engineering as part of design &technology.
It is likely that most if not all the design &make assignments in your curriculum willinvolve pupils working as individuals ratherthan as members of a team. This is in partcaused by the necessity to assess pupils onan individual basis. However it is only when adesign & make assignment is too complex foran individual pupil that it will require asystems engineering approach for successfulcompletion. A suitably complex designing andmaking assignment will require pupils todesign and make individual items that
Creating a systems engineering designing and making assignment
depend on their interaction with one anotherfor good performance.
You can use the following three-phaseapproach to plan for a systems engineeringdesigning and making assignment.
Phase 1 Achieving commitmentIdentify an ambitious design and makeassignment that you think pupils might findattractive. Here are some possibilities.
KS3 – the scary story–– designing a puppetperformanceKS3 – the haunted house – designing a ghosttrain rideKS4 – the white-knuckle ride – designing atheme parkKS4 – the smart room – designing aninteractive environmentKS4 – the safe house – designing an intruderproof house
Use the attractiveness of this idea:• To get the commitment of senior
management,
• To get commitment from three teachers –one maths, one science, one design &technology,
• To get the release of large blocks of timewhere team teaching can take place.
Phase 2 Use the audit approachEnsure the idea is related to the scheme ofwork or specification and is large enough inscope to require pupils to collaborate. Auditfrom a design & technology perspective toensure there is a range of demanding designdecisions to be made.
Consider improvements that would involveexplicit use of maths and science. Developpart constructed starting elements so thatthe task isn’t overwhelming.
Phase 3 Detail the teachingIdentify small task activity in single subjectlessons (maths, science and design &technology) to provide knowledge, skill andunderstanding that is likely to be useful intackling the designing and makingassignment.
Make the best use of subject expertise bythinking through the design decision path thatthe groups of pupils might take and how youcan support them by enabling the following:
• Use of systems thinking,• Use of design & technology subject
knowledge,• Use of maths subject knowledge,• Use of science subject knowledge.
Organise the availability of members of theteaching team so that they can provideappropriate support for identified criticalmoments in the designing and making
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assignment. It is likely that the design &technology teacher will need to be presentthroughout the entire designing and makingprocess.
The maths and science teachers will need tobe present when design decisions relevant totheir specialisms are being made. They arenot critical during the making process. Theywill be extremely useful during modificationand evaluation sessions.
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Name of School
Question Response
Did you use the audit approach toidentifying design decisions in a singledesigning & making assignment at KS3?
What did it reveal?
What changes, if any, did you makeas a result?
Did you use the audit approach toidentifying design decisions in asequence of designing & makingassignments at KS3?
What did it reveal?
What changes, if any, did you makeas a result?
Did you identify any links withmaths and science in the designdecisions made in any of the designingand making assignments at KS3?If so what were these links?
What changes did you make as a
result?
Please look at the next page
Engineering the links between design & technology, maths and science KS3 feedback
Question Response
Please provide details of any designingand making assignments taught inyour school that make good use oflinks with maths and science at KS3.
Please send this completed form to Richard Hamer.
As an attachment to [email protected]
As a fax to 01252 383 237
Thank you for completing the feedback.
page 24
page 25
Engineering the links between design & technology, maths and science KS4 feedback
Name of School Focus Area
Question Response
Did you use the audit approach toidentifying design decisions in a singledesigning & making assignment at KS4?
What did it reveal?
What changes, if any, did you makeas a result?
Did you use the audit approach toidentifying design decisions in asequence of designing & makingassignments at KS4?
What did it reveal?
What changes, if any, did you make asa result?
Did you identify any links with mathsand science in the design decisionsmade in any of the designing andmaking assignments at KS4? If sowhat were these links?
What changes did you make as a
result?
Please look at the next page
Question Response
Please provide details of any designingand making assignments taught in yourschool that make good use of linkswith maths and science at KS4.
Please send this completed form to Richard Hamer.
As an attachment to [email protected]
As a fax to 01252 383 237
Thank you for completing the feedback.
page 26
Systems engineering designing and making assignment feedback for KS3
Name of School Focus Area
Question Response
Did you create a systems engineeringdesigning and making assignment?If yes, please comment on how usefulyou found the following.
The Phase 1 approach to achievingcommitment
The Phase 2 approach to using theaudit approach
The Phase 3 approach to planningthe teaching
Please look at the next page page 27
Question Response
Please provide details of any systemsengineering designing and makingassignments taught in your school atKS3.
Please send this completed form to Richard Hamer.
As an attachment to [email protected]
As a fax to 01252 383 237
Thank you for completing the feedback.
page 28
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Systems engineering designing and making assignment feedback for KS4
Name of School Focus Area
Question Response
Did you create a systems engineeringdesigning and making assignment?If yes, please comment on how usefulyou found the following.
The Phase 1 approach to achievingcommitment
The Phase 2 approach to using theaudit approach
The Phase 3 approach to planningthe teaching
Please look at the next page
Question Response
Please provide details of any systemsengineering designing and makingassignments taught in your school atKS4.
Please send this completed form to Richard Hamer.
As an attachment to [email protected]
As a fax to 01252 383 237
Thank you for completing the feedback.
page 30
Big ideas are engineered: a resource for schools
page 31
Case studies are a useful and effective wayof bringing the world outside school into theclassroom. In this section you will findguidance on using the studies, 5 studies, anda feedback sheet to allow you to let theauthors know how you are using the studiesand how they might be improved.
The first case study, Calculated fitness, is ashort study that shows how equipment in amodern gymnasium uses simple mathematicsto provide performance information to thoseusing the equipment.
The second case study, To the power of two,describes the HybriDrive system developed byBAE Systems engineers to help decreasepollution caused by buses.
The third case study is in two parts. Part 1,A balanced approach to transport, describesthe thinking behind the development of the
Segway, a self balancing, electrically poweredpersonal transporter. Part 2, Designingmagic, describes in more detail how theSegway was developed and how it works.
The fourth case study, It’s all in the software,describes how advances in the technology ofdisplay systems have led to changes in theway aircraft are controlled.
The final case study, Losing power, describeswhat goes wrong when systems engineeringfails, in this case the power supply disruptionthat took place in northern USA and Canadain the summer of 2003.
Please use the feedback sheet to provide theauthors with information on how you usedthe case studies, their effectiveness andhow they might be improved.
Introduction to the case studies
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As the basis for a whole class teacher leddiscussionSome of the information in the case studiesmay be quite new to you and, as such, theyprovide useful inset in terms of subjectknowledge. You can use the information andimages in the case studies as the basis for alesson in which you tell the story ‘from thefront’, without giving the students the printedmaterial. You can produce a series ofoverhead projector transparencies orPowerPoint slides from the printed materialsand use these to construct a question/answer based lesson that moves your classthrough the exposition.
This has the advantage of providing acompletely customised approach although itmight be difficult to keep the concentration ofa wide range of ability through out the lessonwith this approach. It also has thedisadvantage that it requires a lot ofpreparation time.
As individual reflective reading and smallgroup discussionYou may wish to give each pupil a copy of acase study. If so it is important to explain thestructure of the case studies to your pupils.Tell them that the studies are in two parts.
The first is about a product that was de-signed using systems engineering. It willdescribe some or all of the following:
• What it does• How it works• What it is for• Who will use it• How it is used• How it is sold or marketed
By reading part 1 of the study they will gaininsight and understanding of what is achievedby systems engineering.
The second part is about how the product
was designed and produced. It will describesome or all of the following:
• Which engineers and designers wereinvolved
• Which engineering knowledge and skillswere required
• How these were used to develop thesystems
• How the project was managedInceptionDevelopmentManufactureInstallationTraining and supportEventual disposal
By reading part 2 pupils will learn what itmeans to do systems engineering and beable to apply these principles to their ownproject work.
Explain that there are several devices in the
studies to help make them reading themactive so that they are easier to learn from.These are:
• Discussion pointsQuestions for the reader to discusswith other pupils
• ResearchOpportunities to find out moreoutside school time
• ActivitiesSpecific questions requiring writtenanswers
• LinksWebsites with more relevantinformation
Explain that using a Systems Case Study isnot like doing a worksheet. It treats themmuch more like ‘grown ups’ reading an articlein a magazine or a professional journal,expecting them to read carefully and use thequestions and research sections to develop
Using the Systems Engineering Case Studies
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their understanding. Tell them that it is quitealright to underline new words they don’tunderstand yet or draw circles around textthey find difficult. The aim of reading thestudy is to increase their understanding and ifthey understood it all to begin with thenreading the study wouldn’t be achieving that.You might find it useful to make an overheadtransparency or PowerPoint slide of parts ofthe study and project it with annotations.
Using several case studies simultaneouslywith a classThis is a more complex way of using theprinted materials and should only be usedonce students have become familiar with andsuccessful at using the case studies.
• Organise the students into groups -five groups of four for example.
• Give each group a different casestudy.
• Ask each group to read the studyand prepare a short oral report on,
for example, the way the productwas manufactured. Give the groupsa time limit for this task, 15 minutesmaximum.
• Each group then reports back to thewhole class (2 minutes maximumfor each feedback) and you note keypoints on the board.
• You then use a whole class question- answer session based on the keypoints to develop the class’sunderstanding of manufacturing andthe principles of manufacturing thatcan be applied to the production anyproduct. You can use this approachto develop understanding about arange of issues concerned withsystems engineering.
Writing your own case studiesOnce you and your pupils are familiar with thecase study approach to exploring systemsengineering you may find that they are able toresearch and write their own case studies.There are several approaches to this task.
You, the teacher, carry out most if not all ofthe research and provide your pupils with aninformation pack from which each pupildevelops their own case study. An alternativeto this is for the pupils to use the informationpack in groups and work collaboratively todevelop the case study.
You, the teacher, require the pupils to carryout the research so that they develop theirown information pack from which they writethe case study. There are several variationson this. Each pupil carries out their ownresearch and writes their own case study. Thepupils work in groups to carry out theresearch and use the information to write
individual case studies. The pupils work ingroups to carry out the research and write thecase studies as a group activity. You canmake the task demand extra communicationskills by requiring pupils to prepareinformation packs that are then used by otherpupils to prepare case studies.
If you are fortunate enough to have a BAESystems engineer visit your school you canarrange for him or her to be interviewed bypupils as a source of information for casestudy writing and also as a judge of casestudies that have been produced
The format of the case studies can vary. Theycan take the form of written illustrated piecesas in this BAE Systems Engineering pack. Orthey can take the form of live presentation tothe rest of the class. These can be simpleoral presentations supported by flip charts oroverhead projection transparencies or fullblown PowerPoint presentations.