Fundamentals Of Systems Engineering
Fundamentals ofSystems EngineeringProf. Olivier L. de WeckSession 8Systems IntegrationInterface Management1
2
3
Outline Why is interface management important? System failures due to interfaces Working with partners and suppliers Interface Management Types of Interfaces Design Structure Matrix (DSM) Interface Control Documents (ICD) – NASA Approach System Integration Sequencing of Integration Role of Standards4
System Interfaces – internal vs. externalSystem BoundaryInternal InterfacesExternal Interfaces Canon Inc. All rights reserved. This content is excluded from our Creative Commonslicense. For more information, see http://ocw.mit.edu/help/faq-fair-use/.Source: Canon (Powershot S10)5
Interface-induced Failures Much effort is spent on designing individual parts of asystem Functionality, tolerances, mean-time-between-failure (MTBF) Interfaces are often neglected and can be the “weak points” Bottlenecks, Structural failures, Erroneous function callsMerging from side roadto main road (Russia 2007)Torque Failure (MIT 2005)Ariane 501Accident report (1996)As a result of its failure, the active inertialreference system transmitted essentiallydiagnostic information to the launcher'smain computer, where it was interpretedas flight data and used for flight controlcalculations. On the basis of thosecalculations the main computercommanded the booster nozzles, andsomewhat later the main engine nozzlealso, to make a large correction for anattitude deviation that had not occurred. source unknown. All rights reserved. This content is excluded from our CreativeCommons license. For more information, see http://ocw.mit.edu/help/faq-fair-use/.6
Working with SuppliersComplex engineered systems are increasingly designed (and built)by geographically distributed teams, requiring careful definition of interfaces source unknown. All rights reserved. This content is excluded from our CreativeCommons license. For more information, see http://ocw.mit.edu/help/faq-fair-use/.7
Interface Management Importance Complex systems have manyinterfaces Common interfaces reducecomplexity System architecture drivesthe types of interfaces to beutilized in the design process Clear interface identificationand definition reduces risk Most of the problems insystems are at the interfaces. Verification of all interfaces iscritical for ensuringcompatibility and operation8
Experiences with Interfaces Turn to your partner exercise (5 min) What was an instance in your past experience werecarefully defining and managing an interface wascritical? Discuss with your partner. Share.9
Outline Why is interface management important? System failures due to interfaces Working with partners and suppliers Interface Management Types of Interfaces Design Structure Matrix (DSM) Interface Control Documents (ICD) – NASA Approach System Integration Sequencing of Integration Role of Standards10
\Examples of Interfacesmass flowValvemTankmomentumRocketHeatExchangerSolar CellF tPayloadHeat fluxQElectricalpower fluxUIAirweb site(URL)MotionSensorNPRRadiohtml t11
4 Canonical Types of Interfaces Physical Connection (always symmetric) If A connects to B, B must also connect to A. Energy Flow Mass Flow Information Flow12
Physical ConnectionTwo parts are in direct physical connection if they touch each other examples: rollers, brake pad & disk, finger & touchscreen have a reversible connection between them examples: electrical connectors, USB port/cable, latch mechanism, bolts & nuts are permanently connected to each other examples: rivets, spot-welded, fusing, compiling (?)Quantifiable interaction2 Force [N], Torque [Nm]1OPMMainMotor3BTRDriveClutch1Main MotorK Clutch3BTR ClutchEngaging2K DriveClutchDSM123Important Note:physical connectionimplies symmetricentries in the DSM(action reaction)13
Examples of Physical ConnectionIrreversible structural linksReversible structural linksStrut ub1.oSub2.oMain.execompilingStrut 2RJ-45 jackconnectingplug14
Energy Flow Energy Flow is present if there is a net exchange of workbetween two components Power dW/dt [J/s W] Can take on different forms Electrical Power (most common in products) DC Power (12V, 5V, 24V, ), Power Current * Voltage AC Power (120 V 60Hz, 220V 50Hz, ) Thermal Power Heat flux: dQ/dt Conduction, Convection, Radiation RF Power Microwaves (2.4 GHz, 5.8 GHz, ) Mechanical Power Linear: Power Force * velocity Rotary: Power Torque * angular rate Energy Flow typically usually implies a physical connection (butnot always !) Wires, conducting surface15
Energy Flow (cont.)Energy Flow is typically directed from source to sinkOPMDSM1Unfused TonerPaperHeat RollHeatRollFusingHeatPaper2Belt12Heat Energy is transferredfrom system 1 to system 2Important Note:typically we first map thedesired interactions, lateras we know more also theundesired ones (e.g. wasteheat flux)16
Mass Flow Mass Flow implies that matter is being exchanged betweentwo elements (or subsystems) mass flow dm/dt [kg/sec] Fluids cooling liquid (refrigerant), fuel, water, Gases air, exhaust gas, Solids toner, paper (media in general), Typically implies an underlying physical connection Mass flow is typically directed from source to sink can form a continuous loop17
Mass Flow (cont.)Examplesdischargelamppositive ionnegative leanlampCleaning ingNegative Toner12Mass is transferredfrom system 1 to system 218
Information FlowMany modern electro-mechanical systems have replaced functions previouslyimplemented with mechanical elements in softwareRequired for Interactions with the user/operator GUI, I/ORequired for interactions with other devices Analog (ADC, DAC), Digital (DIO), Wireless (e.g. IEEE 802.11)Required for internal device controls Sensors Actuators Controllers Filters, Amplifiers, Information flow is always directed Telemetry (sensor data) how is my system doing? Command data this is what I want my system to do19
Information Flow (cont.)Control cesignalOperatorXerography: ImagingOpticalSystemOPMOriginal documentLampLaser temImagingDigital ImageFile12Information is transferredfrom system 1 to system 220
Outline Why is interface management important? System failures due to interfaces Working with partners and suppliers Interface Management Types of Interfaces Design Structure Matrix (DSM) Interface Control Documents (ICD) – NASA Approach System Integration Sequencing of Integration Role of Standards21
DSM Captures Form Connectivity er171PumpValveFilterMotor11 37 151151DSMKey1111 3NumberTypeFlag0No Connection erValvePumpControllerSample SystemArchitecture Definition:The embodiment of concept,and the allocation ofphysical/informational function(process) to elements of form(objects) and definition ofstructural interfaces among theobjects15 DSM captures connectivity ofcomponents architecture DSM provides analysiscapability not present in atraditional schematic22
Background Design Structure Matrix (DSM) Synonyms (a.k.a.) Design Dependency Matrix N2-Matrix, N2-Diagram Adjacency Matrix (Graph Theory) Based on Fundamental Work by Don Stewart andSteve Eppinger Donald V. Steward, Aug. 1981, IEEE Transactions onEngineering Management Steve Eppinger et al., 1994, Research in EngineeringDesign Matrix Representation of Product Architecture Most literature simply uses “binary” DSMs Need more process related details to connect to physics23
Refrigerator Liaison Diagram (Level 1)1. Door2. Condenser3. Power Supply3104. Hinge45. Cabinet6. Thermostat7. Refrigerant51798. Evaporator9. Freezer Door26810. Compressor24
Key Idea Map to Matrix Matrix 7XX8XX9XXLiaison DiagramKenmore Refrigerator 2.5 cu ftXXX10What types of interfaces exist?25
Classes of Object-Process-Operand LinksObject-based DSM- “chunks” of producton main diagonal-interconnections:-physical-energy-mass flow-informationProcess ctionForces,Torques[N, Nm]Force orTorqueTransmittingbolts, washers,rivets, spotwelds EnergyFlowWork[J]Electricity orHeatTransmittingcopper wires,microwaves, MassFlowMass[kg]Fluid, Gas orSolid MatterTransmittingfuel lines, airducts, exhaustpipes InformationFlowBits[-]Data orCommandTransmittingmicro-switches,wireless RF,humansNote: In many cases, in order for an energy, mass or information flow to exist,there also needs to be a physical connection, but not always26
Refrigerator Level -1 DSMPhysical ConnectionsMass FlowsEnergy FlowsInformation Flows27
General Process for Generating a DSM Top Down (design and architecting) Generate System OPMHide attributes and statesCollapse all processes into “tagged” structural linksGenerate DSM Bottom-Up (reverse engineering) Select system/product to be modeled Perform product dissection Carefully document the following: Parts List/Bill of Materials Liaison Diagram (shows physical connections) Infer other connections based on reverseengineering/knowledge of functions: mass flow, energy flow, info flow Manipulate DSM clustering28
Xerox iGen3 Baseline Design Structure Matrix (DSM)GUIFeederSoftwarePrint EngineImage PathStackerPrint EngineMedia Path1234KeyptaodHVLV5, mhPrint EngineMarking PathPrint EngineControl PathPrint EngineFrameSuh. E.S., Furst M.R., Mihalyov K.J, de Weck O., “Technology Infusionfor Complex Systems: A Framework and Case Study”, SystemsEngineering, 13 (2), 186-203, Summer 2010LegendPhysical connectionMass flowEnergy flowInformation flow1 23 4PaperTonerair (purified / ready for use)OzoneDirtHigh VoltageLow VoltageDC VoltageMechanical energy (translation, rotation, etc )Heat energy (Fuser only)Base iGen DSMTotal number of DSM ElementsTotal number of physical connectionsTotal number of mass flow connectionsTotal number of energy flow connectionsTotal number of information flow connectionsNumber of Base DSM cellsNumber of non-empty cellsSparsity (Nonzero Fraction NZF) John Wiley & Sons, Inc. All rights reserved. This content is excluded from our CreativeCommons license. For more information, see 52797210330.03729
Detailed Reverse Engineering DSM .Define which product or system to modelAssemble product documentationCreate product breakdown structureStart a blank DSM spreadsheet for example in ExcelLabel the rows and columns of the DSM with both an ID number 1 N and acomponent/subsystem nameStart by mapping all the physical connections in the systemDouble-check the physical connectionsMap out mass flows along physical connectionsDouble-check mass flows from start to originMap out the energy flows along physical connectionsDouble-check energy flows from start to finishMap out information flows following physical connectionsDouble-check information flows in the systemMap interactions (flows) in the system that do not follow physical connectionsReorder the DSM to reveal “modules”Suh E.S., de Weck O.L., Furst M., Mihalyov K.,Double-check accuracy of DSM“Estimating the Impact of Technology Infusion”,Sign off and publishXerox Technical Report, Accession NumberX200700206, Xerox Corporation, January 200830
High Level Product Architecture (Xerox)Front-endSystem(Media Input)Imaging andMarkingEngineFinishing System31
Outline Why is interface management important? System failures due to interfaces Working with partners and suppliers Interface Management Types of Interfaces Design Structure Matrix (DSM) Interface Control Documents (ICD) – NASA Approach System Integration Sequencing of Integration Role of Standards32
Interface Management Process1212Interface ManagementNASA Systems Engineering Handbook33
Interface Management Process Purpose12The Interface Management Process is used to: Establish and use formal interface management to assist incontrolling system product development efforts especiallywhen the efforts are divided between government programs,contractors, and/or geographically diverse technical teamswithin the same program or project Maintain interface definition and compliance among the endproducts and enabling products that compose the system aswell as with other systems with which the end products andenabling products must interoperate.34
Key Interface Documentation12 Interface Requirements Document (IRD) - Defines the functional,performance, electrical, environmental, human, and physicalrequirements and constraints that exist at a common boundary betweentwo or more functions, system elements, configuration items, orsystems. Interface requirements include both logical and physical interfaces. Interface Control Document or Interface Control Drawing (ICD)- Details the physical interface between two system elements, includingthe number and types of connectors, electrical parameters, mechanicalproperties, and environmental constraints. The ICD identifies the design solution to the interface requirement. ICDs are useful when separate organizations are developing design solutions tobe adhered to at a particular interface. Interface Definition Document (IDD) - A unilateral documentcontrolled by the end item provider, and provides the details of theinterface for a design solution that is already established. This document is sometimes referred to as a “one-sided ICD.” The user must then design the interface of the system to be compatible withthe already existing design interface.35
Interface Management ProcessActivities12OutputInputThis image is in the public domain.36
Outline Why is interface management important? System failures due to interfaces Working with partners and suppliers Interface Management Types of Interfaces Design Structure Matrix (DSM) Interface Control Documents (ICD) – NASA Approach System Integration Sequencing of Integration Role of Standards37
System Integration System integration is the process of deliberate assembly of theparts of the system into a functioning whole Physical assembly of parts Connecting different conduits, hoses Filling in various kinds of consumables Connecting electronics to power sources, avionics etc (often withwire harnesses) Uploading of test and operational software The sequence in which integration occurs may be important (see paperby Ben-Asher et al.) In complex systems many errors are only discovered during systemintegration and test38
Systems Integration SequencingSingle-Stage IntegrationIncremental Integration Integration Sequence can be optimized All-in-one vs. incremental integration Expected time duration distribution for systemintegration depends on sequence and uncertaintyRef: Tahan and Ben-Asher [2004] John Wiley & Sons, Inc. All rights reserved. This content is excluded from our CreativeCommons license. For more information, see http://ocw.mit.edu/help/faq-fair-use/.39
Concept Question 8: Role of Standards Industry Standards are established to simplifyinterface management. Which of thefollowing standards are you familiar with? IEEE 802.11g MIL-STD-1553 RS-232C Bba J23100 Others Answer Concept Question 8(see supplemental files)40
Summary Lecture SE6Why is interface management important? System failures due to interfaces Working with partners and suppliersInterface Management Types of Interfaces Design Structure Matrix (DSM) as a Interface Control Documents (ICD) – NASA Approach Many other organizations use ICDs in one way or anotherSystem Integration Needs to be carefully planned Sequence of integration may be very important, area of active researchin Systems Engineering Industry Standards for Interfaces are critical41
MIT OpenCourseWarehttp://ocw.mit.edu16.842 Fundamentals of Systems EngineeringFall 2015For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.
Engineering Management Steve Eppinger et al., 1994, Research in Engineering Design Matrix Representation of Product Architecture Most literature simply uses “binary” DSMs Need more process related details to connect to physics 23
Materials Science and Engineering, Mechanical Engineering, Production Engineering, Chemical Engineering, Textile Engineering, Nuclear Engineering, Electrical Engineering, Civil Engineering, other related Engineering discipline Energy Resources Engineering (ERE) The students’ academic background should be: Mechanical Power Engineering, Energy .
Pass Google ADWORDS-FUNDAMENTALS Exam with 100% Guarantee Free Download Real Questions & Answers PDF and VCE file from: . A key benefit of My Client Center (MCC) is that it allows: . Latest Google exams,latest ADWORDS-FUNDAMENTALS dumps,ADWORDS-FUNDAMENTALS pdf,ADWORDS-FUNDAMENTALS vce,ADWORDS-FUNDAMENTALS dumps,ADWORDS-FUNDAMENTALS exam .
—Civil Engineering Systems three major branches of civil engineering: construction engineering, structural engineering, and transportation engineering. —Environmental Engineering the fundamentals and applications of waterresources engineering, pollution in natural systems (water an
Systems Engineering Is Systems engineering consists of two significant disciplines: the technical knowledge domain in which the systems engineer operates, and systems engineering management. This book focuses on the process of systems engineering management. Three commonly used definitions of
that leverages systems engineering in the transition to team-based engineering for conception, design, and implementation. Use of Systems Engineering. Making effective engineering decisions via hazards and risk analysis to integrate all engineering topics (such as cyber security and SCCF) into a single engineering process. Risk Informed Engineering
Careers in Engineering Guide the brighter choice. Contents ABOUT LSBU 4–5 BUILDING SERVICES ENGINEERING 6–7 CHEMICAL AND PETROLEUM ENGINEERING 8–9 CIVIL ENGINEERING 10–11 ELECTRICAL AND ELECTRONIC ENGINEERING 12–13 MECHANICAL ENGINEERING 14–15 MECHATRONICS ENGINEERING 16–17 PRODUCT DESIGN ENGINEERING 18–19 An engineering degree is a big challenge to take on. There is no denying .
OLE MISS ENGINEERING RECOMMENDED COURSE SCHEDULES Biomedical engineering Chemical engineering Civil engineering Computer engineering Computer science Electrical engineering General engineering Geological engineering Geology Mechanical engineering Visit engineering.olemiss.edu/advising for full course information.
engineering fundamentals, and an engineering specialization to the solution of complex engineering problems. PO-2 . J.E. Bailey and D.F. Ollis, Biochemical Engineering Fundamentals, McGraw Hill Higher Education, 2nd edition, 1986 4. James M. Lee, Biochemical Engineering. Prentice Hall.
