system analysis - manasbajaj - intercax - sysml2wg omg ......dec 08, 2015 · sysml currently...

SystemAnalysisRequirementsforSysML 2.0

ManasBajaj,PhDCo-Founder &ChiefSystemsOfficer

[email protected]

SysML2WGMeeting,OMGTechnicalMeetingLaJolla,CA,Dec8,2015

Contents• Goal• Analysis– Concept– IssuesinSysML1.4– EffectivenessMeasures– SMEServicestoSupportAnalysis– HybridSUVChangeScenario

• Howcanyougetinvolved?

Copyright2015IntercaxLLC 2

Starting Point

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

• Supportvarioustypesofanalysesandexecutiontools

• 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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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.Transformationsbetweendesign-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– SysMLprovideslow-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 13

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 15

Copyright2015InterCAXLLC 16

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

Issue#3– DesignAnalysisModelTransformationsforSimulation-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,orSysML andnon-SysMLconstructs,e.g.– SysMLparametrics equation-basedmodels,– SysML statemachinesstate-basedmodels,– SysML IBD/Activityflow-basedmodels,– SysMLgraph-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– IssuesinSysML1.4– EffectivenessMeasures– SMEServicestoSupportAnalysis

• Seelatestversionofthespreadsheet– HybridSUVChangeScenario



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-basedintegrals)• CFDmodelusing2D/3DCADoftheHSUV

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


Scenario#2Vehiclefailstomeetfuelefficiencyrequirement

• Searchmodelrepositoryforfuelefficiencyanalysismodelsused,andresultsets(HSUVdesign,environment,anddriveprofileused)

• Compareresultsetwiththeactualprototyped/builtvehicle.

• Setupandperformnewanalyses• Providerecommendationstothedesignteam


Scenario#3Recallcatalyticconverter

• TBD


NextSteps• Reviewthisdeckandemailfeedbackto:

[email protected]• Participate– Sendmeanemail– Followinghaveexpressedinterest

• MichaelChonoles (Independent,Astah)• BjornCole(JPL)• GeorgeWalley (Ford)• Hans-Peter(ESA)

– Setupasimpleprocesstoreviewandexpandconcepts– Bringissues/examplesforSysML2.0


system analysis - manasbajaj - intercax - sysml2wg omg ......dec 08, 2015 · sysml currently...

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