System Analysis - ManasBajaj - Intercax - SysML2WG OMG … 2016. 3. 16. · System Analysis...

SystemAnalysisRequirementsforSysML 2.0

ManasBajaj,PhDCo-Founder&ChiefSystemsOfficer

[email protected]

SysML2WGMeeting,OMGTechnicalMeetingReston,VA,Mar15,2016

Team• Manas Bajaj,Intercax [leadforSysML 2WG]• BjornCole,NASAJPL• AhsanQamar,Ford• GeorgeWalley,Ford

Howdowework?=GoogleDrivespace(hostedbyIntercax)forallmemberstojotdowntheirideasandthoughts.Teammeetingstorefineandmergeideasintoacoherentstory.

Ifyouwouldliketocontribute,[email protected]

Copyright2015IntercaxLLC 2

Contents• Goal• Analysis– Concept– IssuesinSysML 1.4– EffectivenessMeasures– SMEServicestoSupportAnalysis– HybridSUVChangeScenario

• Howcanyougetinvolved?


StartingPoint

The next-generation modeling language must include precise semanticsthat avoid ambiguity and enable a concise representation of the concepts.SysML currently leverages the UML metamodel for much of its semanticfoundations. The language must be based on a well-specified logicalformalism that can leverage the model for a broad range of analysis andmodel checking. This includes the ability to validate that the model iscorrect and consistent, and the ability to answer questions such as theimpact of a requirement or design change, or the assessment of how afailure could propagate through a system. The language and tools mustalso integrate with a diverse range of equation solvers and executionenvironments. The language must also be able to represent, relate, andpresent quantitative data sets that can vary with time and space, andhave probability distributions.

EvolvingSysMLandtheSystemModelingEnvironmenttoSupportMBSEDraft(February1,2015)S.Friedenthal/R.Burkhart

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SystemModelingEnvironment

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OMGTechnicalMeetingCambridgeMA,Sep22-23,2015

Goals

• Analysismustbeseamlessintegratedwithsystemdevelopmentandoperation

• Supportvarioustypesofsystem analysesandexecutiontools

• Manageanalysismodelsandrelateresultstodecisions

• Improveduserinteractiontodefine/generate,execute,archiveanalysismodels(analysislifecycle)

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WhatisAnalysis?• Systematicinvestigationofarealorplannedsystemto(a)compareandselectcandidatesystemarchitectures,or(b)determinecauses&resolutionsoffailures/exceptions– SEBoK - http://goo.gl/RCtAKt– NASASEHandbook(2007) - http://goo.gl/iVBVES

• Examples(design,manufacturing,operation)– Comparethemileage/costforasetofcardesigns–Whatisthedesignimpactofarequirementchange?– Optimizemanufacturingprocesstomaxyield/cost–Whatpartsmayhavecausedafunctiontofail?

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Scope=System-LevelAnalyses• Analysisthathaswide-rangingorcross-cuttingeffectinacomplicatedsystem- greaterthan100’sofpartsorinvolvingmorethanoneacademicdisciplineofengineering– Simulationofsciencereturnovertimefromaninterplanetaryprobe

– Evaluationoffueleconomyoveracourse– Impactassessmentofchangeinahigh-levelrequirement

• Analysisineachdomain(mechanical,electrical,software)consideredbecauseoftheirsystem-levelimpactbutnottheprimarysubjectofourinvestigation


SystemAnalysisRoles• Customer =Engineer/managerwhorequirestechnicalinputbeforeadecisionismade.– Focus =Useanalysistorapidlyexploretheproblemspace,visualizeresults,anddevelopkeyinsights

• Performer =Engineerwhoformulatestheapproach,selectsorbuildsappropriatemodelsofphysicsorbehavior,andappliesskillstoprovidingtechnicalinsight– Focus =Studythedomain,anddevelopanalysismodelsofvarying-fidelities,deepknowledgeofdomainandtools

• Typically– CustomerandPerformermaybedifferentgroupsofindividualsinlargeorganizations,OR

– SamepersoninasmallorganizationCopyright2015IntercaxLLC 10

TypesofAnalyses


• QuantitativeAnalyses,e.g.computingMoEs• QualitativeAnalyses,e.g.IfIchange(increase)X,willYchange(increase/decrease)?

TypesofAnalysesRequirementsAnalysis[new]

• Analyzingfunctionalscenariosandrequirementscapturedinthemodel

• RequirementsQualityAnalysis– Aretheresituation/scenariosthesystemwillencounterthatarenot

coveredbytheformulatedrequirements[Coverage]?– Arethereconflicting,oroverlappingrequirementsbetweendifferent

enterprisesystems[LogicalConsistency]?– Arethererequirements/constraintthathavenomappingtoaphysical

realization[DesignCompleteness]?– Isthereanydesignspaceleft?[PhysicalConsistency]– Didweblowoutthecostorcorruptthebusinesscase?[Viability]– Didwemakestatementsthathaveaprecise,logicalconditionthatcan

betested?[Verifiability]– Canwesimulateafeasibleconceptortwoforthestakeholdersfor

theiracceptance[Validation]?


• Timing-basedRequirements– Canwerepresentrequirementasaplotofdesiredsystemresponseversustime?

– Canwedesignateperformanceregionsinthisplotandidentifysystemstates?


TypesofAnalysesRequirementsAnalysis[new]– cont.

• Programmaticanalysissupportsprojectmanagementbyprovidingmetricsontherateofprogress,theestimatedamountofworktogo,andpossibledivergencesbetweenplannedandexpectedtechnicaloutcomes.Examplesofthisaskthefollowingquestions:– Howmanyrequirementsaretestedornotsatisfied?– Arethereconcernsthatarenotaddressedyet?– Howtodefineameasureonprogressbasedontheinformation

availableatthesystem-level?– Howmuchworkhasbeendonesofar?– Howmuchworkislefttogo?– Howmuchreworkwillagivenchangegenerate[impact

assessment]?– Istheworkplannedwell-allocatedorisitoveremphasizingone

areaatthecostofothers?


TypesofAnalysesProgrammaticAnalysis[new]

• Determineifappropriateresourcesarebeingmadeavailabletoachieveprojectgoals.– Technicalresources,e.g.,mass,power,fuel.– Externalresource,e.g.costorschedule(overlapwithprogrammaticanalysis).

– Inamoreenterprise- ormarket-orientedproject,theresourcesexaminedmayincludeusefulinfrastructuresuchasapowergridcapacityorfuelingnetwork.


TypesofAnalysesResourceAnalysis[new]

BroaderIssues

• Howdowemathematicallyrepresentassumptionsusedinananalysismodel?

• Howdowemathematicallyrepresentthefidelityofanalysis/analysismodel,anduseittogradeanalysismodels?

• Howdowedecideifweneedahigherfidelityanalysisfordecisionmaking,oristhecurrentanalysis“goodenough”?


TypesofAnalyses


• QuantitativeAnalyses,e.g.computingMoEs• QualitativeAnalyses,e.g.IfIchange(increase)X,willYchange(increase/decrease)?

Analysisduringsystemdevelopmentandoperations


CostAnalysis

DesignandAnalysisareseparatemodels


SystemDefinition(Structure,Behavior,…)

CostAnalysisCostAnalysis

CostAnalysisCostAnalysisPowerAnalysis

CostAnalysisCostAnalysisReliabilityAnalysis

CostAnalysisCostAnalysisXAnalysis

1.Transformations betweendesign-analysismodels–generationandflowofinformation

2.Multiplefidelitiesforthesameanalysis

…

Wheredoesthesystemanalysismodellive?


Pre-SysMLworld

SysMLworld

SystemDefinition(Document)

Excel

MATLAB

Manual,humantransformer

SystemDefinition

Mathanalysisandsolvertools

CostAnalysis

PowerAnalysis

…

Mathematica

Excel

MATLAB

Mathematica

Semantictransformation

MostlysyntactictransformationSysMLmodel




Issue#1– Analysisisamissingconcept,WheredoIstart?

• AnalysisisamissingconceptinSysML– SysML provideslow-levelmodelingconstructs(e.g.blocks,constraintblocks,activities)thatcanbeusedforrepresentingvariousSEartifacts.But,

– Missinghigh-levelSEconceptssuchas“System”,“Analysis”,“Decision”,“TradeStudy”

• Givenasystemdefinition/design,can’teasilyquery– Whatanalyses willbeorhavebeenperformedonthesystem?

– Whataretheresultsoftheanalyses?– Whatissuesdidtheanalysisreveal?– Whatarchitecturedecisionsweretakenfromtheanalyses?

– Whereistherevisedversionofthearchitecture?Copyright2015Intercax LLC 22

Issue#2– Noclearwaytorepresentandqueryartifactsrelatedtoanalyses

• Nodirectandclearwaytorepresent:– Objectiveoftheanalysis– SystemMOEsbeinganalyzed– Analysismodels(multiplefidelities)forcomputingMOEs– Executionofanalysismodels(tools,versions,…)– Resultsofexecutinganalysismodels– Decisionstakenfromanalysismodels– Analysisrelations

• Decomposeacomplexanalysisintosub-analyses• Upstreamanddownstreamanalyses


SystemAnalysisMeta-Model(1/2)[ResultofNIST-Intercax Project,2014-2015]

Copyright2015InterCAXLLC 24

Copyright2015InterCAXLLC 25

SystemAnalysisMeta-Model(2/2)[ResultofNIST-Intercax Project,2014-2015]

Issue#3– Design<->AnalysisModelTransformationsforSimulation-BasedDesign

• WheredoIexpressmodeltransformationsbetweendesignandanalysismodels?

• Design->AnalysisModelTransformations– Knowledgecapture-- Whatassumptionsdoesananalysttake?– Executabletransforms-- Changethedesignmodel,updatetheanalysismodelautomatically

• Analysis->DesignModelTransformations– Relateanalysisresultsofthesystemdesign– Reconstructdesignmodelsfromanalysismodels

• Reference– KnowledgeCompositionMethodologyforEfficientAnalysisProblem

FormulationinSimulation-basedDesign(Bajaj,PhDDissertation,2008,GeorgiaTech)• https://smartech.gatech.edu/handle/1853/26639


Issue#3(cont.)• ExpressmathematicaltransformationsbetweenconstructsinSysML,orSysMLandnon-SysMLconstructs,e.g.– SysML parametrics <->equation-basedmodels,– SysML statemachines<->state-basedmodels,– SysML IBD/Activity<->flow-basedmodels,– SysML <->graph-basedmodels

• Currentlythisisnowaytoexpressthesetransformationsexceptforsome“tagging”usingcustomstereotypes

• Potentiallyextendtheviewpointconceptwithmathformalismstogeneratenon-SysMLmodels(viewsbeyondstaticdocuments)


Issue#4– MissingTypesandConfusingUnits

• Systemdefinitionandanalysisneedsarichrepresentationoftypes– Arrays,Lists(ordered/unordered),Sets,…– Matrices(mxn)– Map(key-valuepairs)– TensorsandVectors– MutableandImmutableobjects(constants)– DateandTime– Geographicmap– ProbabilityDistributions


Issue#4– MissingTypesandConfusingUnits(cont.)

• Yes,wehaveaQUDVprofileandalibraryofunitsbutithasn’tbeenuseful– Unitsandquantitydefinitionsarefundamental,shouldn’tbenon-normativeextensions.NotallSysMLtoolimplementthis.

– LibraryofunitsonlySI,missingFPSsystem– Confusinganddifficulttocreatecomplex,derivedunits-- givenvaluetypeskg,m,s,andkg.m/s^2,howdoIcreatethevaluetypeg.cm/s^2 leveragingtheexistingquantitykindsanddimensions?

• Verifyifunitsaresameandautomatedconversion


Issue#5– OperatorsandFunctions• Operators,suchasthese,shouldbeacoreintegralpartofthelanguage– Differentials∂/∂t(ofspace,time,andothervariables)

– Integrals∫ (overspace,time,andothervariables)– Time(temporalproperties)– Probabilities(propertydistributions)– Mathfunctions• Trigonometric,Logarithmic,Hyperbolic,…


Issue#6– Geometry• Lackofgeometricconceptsneededfordesign,analysis,andrequirements,e.g.:– DistancebetweenCGofcompAandcompBshallbenomorethan4.5cm

– ShapeofpartAisaSpherewithradius5cm• Exampleconcepts– Co-ordinatesystems(Rectangular,Polar,etc.)– Primitive2Dshapes(point,line,triangle,rectangle/square,pentagon,…,circle)

– Primitive3Dshapes(3Dpoint,plane,cuboid/cube,sphere,cylinder,cone,…)

– Massproperties(mass,volume,density,boundingboxes,moments-of-inertia,…)


Issue#7– Visualizationofanalysisresults

• Variousformsofvisualizationofanalysisresultsshouldbeavailable– Tables– Plots(2Dand3D)– Customcharts(extensibility)


Issue#8– UniversalUniqueID(UUID)

• UniversalUniqueID(UUID)toidentifyallsystemelements.Wemustfirstidentifythesystem/viewbeinganalyzed,analysismodel,results,anddecisionsrelatedtothat

• UUIDconceptneedstobeapartofthespecandimplementedbyeachSysMLtool.CurrentlyeachtooldefinesitsownIDsystemandsomehavemultiple

• NecessaryforSysMLelementstointeroperateandtraceablewithelementsfromnon-SysMLmodelingtoolsandrepositories(e.g.PLM,ALM,Databases,Resourceontheweb)


Issue#9– VersionandConfigurationManagement

• Versionchain– Whatversionofthesystemarchitecturewasanalyzed?

– Whatversionoftheanalysismodelwasused?– Whatversionofthesolvertoolusedforexecutingtheanalysismodel?

• Configurationcontrol– Whocreatedtheanalysisandwhocanmodify?– Whocanruntheanalysis?– Whocanviewtheresultsoftheanalysis?– Whocanaffectthesystemarchitecturebasedontheanalysis?





EffectivenessMeasures• CanIunambiguouslyrepresentanalysisandrelatedartifactsforasystem,aslistedinIssue#2?

• CanIperformanalysis-relatedqueriesonthesystemarchitecturemodel,aslistedinIssue#1?

• CanIkeeptrackoftheanalysisandrelatedartifactsforfuturelookupandqueries,aslistedinIssues#1,2,9?

• CanIseamlessgenerateanalysismodelsinvarioustools/languagesfromtheSysMLarchitecturemodel,andcanIupdate/synctheanalysismodelifthesystemarchitecturechanges?(Issue#3)


Contents• Goal• Analysis– Concept– IssuesinSysML 1.4– EffectivenessMeasures– SMEServicestoSupportAnalysis• Seelatestversionofthespreadsheet

– HybridSUVChangeScenario• Howcanyougetinvolved?





Scenario#1Gov regulationtoimprovefuelefficiency• Analysisneeds:

– HSUVdesign:Size,Weight,Power,…– Environment:Road,Drag(Air),Traffic,Conditions(city/hwy)– Driver:Drivingprofile

• Analysismodel– Acausal parametricmodel+tradesandoptimization

• Giventhedesign,environment,drivervariables,computefuelefficiency• Giventhetargetfuelefficiencyandavg valuesofenvironmentanddrivervariables,computemaxsize/weightandminpower

– Fidelities• Simpleanalyticalmodel(staticequations)• Complexanalyticalmodel(dynamic,time-based integrals)• CFDmodelusing2D/3DCADoftheHSUV

– Analysis/SimulationTool• Mathematica /MATLABforequation-basedanalyticalmodels• ABAQUS/ANSYSforCFDmodels


Scenario#2Vehiclefailstomeetfuelefficiencyrequirement

• Searchmodelrepositoryforfuelefficiencyanalysismodelsused,andresultsets(HSUVdesign,environment,anddriveprofileused)

• Compareresultsetwiththeactualprototyped/builtvehicle.

• Setupandperformnewanalyses• Providerecommendationstothedesignteam


Scenario#3Recallcatalyticconverter

• TBD




NextSteps• Finishgatheringsystemanalysesneeds[wish-list]fromteammembers

• Developameta-modelinSysML torepresentthefindings,e.g.typesofanalyses

• DevelopawhitepaperwithdetaileddocumentationonsystemanalysisneedsforSysML 2andissuesinSysML 1.x– beyondslideware


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System Analysis - ManasBajaj - Intercax - SysML2WG OMG … 2016. 3. 16. · System Analysis...

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