requirements engineering - present and future hot research topics
TRANSCRIPT
Requirements Engineering: Research topics
CECS 542 Dr.BirgitPenzenstadler 1
Photocredit:SamHull,Unsplash
HotresearchtopicsinRE• PaperbyNuseibehandEasterbrook,2000
• UpdatepaperbyChengandAtleein2007
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CogniIveandsocialsciencesasfoundaIon
• REdrawsonthecogniIveandsocialsciencestoprovideboththeoreIcalgroundingandpracIcaltechniquesforeliciIngandmodellingrequirements:
• Cogni&vepsychologyprovidesanunderstandingofthedifficulIespeoplemayhaveindescribingtheirneeds[62]
• AnthropologyprovidesamethodologicalapproachtoobservinghumanacIviIesthathelpstodeveloparicherunderstandingofhowcomputersystemsmayhelporhinderthoseacIviIes[29].
• SociologyprovidesanunderstandingofthepoliIcalandculturalchangescausedbycomputerisaIon.
• Linguis&csisimportantbecauseREislargelyaboutcommunicaIon.
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Requirementstoelicit
• Boundaries• Stakeholders• Goals• Usertasks/usecasesàAllsoundsfamiliar,right?
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ElicitaIontechniques
• TradiIonaltechniques(surveys,interviews)• GroupelicitaIontechniques(workshops)• Prototyping• Model-driventechniques(e.g.,KAOS)• CogniIvetechniques(cardsorIng)• Contextualtechniques(ethnographics)
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Modelingandanalyzingrequirements
• Enterprisemodeling• Datamodeling• Behaviormodeling• Domainmodeling• ModelingNFRs• Analyzingrequirementsmodels
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CommunicaIngrequirements• REisnotonlyaprocessofdiscoveringandspecifyingrequirements,itisalso
aprocessoffacilitaIngeffecIvecommunicaIonoftheserequirementsamongdifferentstakeholdersàensuringthattheycanberead,analysed,(re-)wriben,andvalidated.
• ThefocusofrequirementsdocumentaIonresearchisocenonspecificaIonlanguagesandnotaIons,withavarietyofformal,semi-formalandinformallanguagessuggestedforthispurpose,fromlogictonaturallanguageàdifferentlanguageshavebeenshowntohavedifferentexpressiveandreasoningcapabiliIes.
• Whatisincreasinglyrecognisedascrucial,however,isrequirementsmanagement–theability,notonlytowriterequirementsbutalsotodosoinaformthatisreadableandtraceablebymany,inordertomanagetheirevoluIonoverIme.
• OneabempttoachievereadabilityhasbeenthedevelopmentofavarietyofdocumentaIonstandardsthatprovideguidelinesforstructuringrequirementsdocuments.
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Agreeingrequirements• Asrequirementsareelicitedandmodelled,maintainingagreementwithall
stakeholderscanbeaproblem,especiallywherestakeholdershavedivergentgoals.
• Recallthatvalida&onistheprocessofestablishingthattherequirementsandmodelselicitedprovideanaccurateaccountofstakeholderrequirements.
• ExplicitlydescribingtherequirementsisanecessaryprecondiIonnotonlyforvalidaIngrequirements,butalsoforresolvingconflictsbetweenstakeholders.
• TechniquessuchasinspecIonandformalanalysistendtoconcentrateonthecoherenceoftherequirementsdescripIons:aretheyconsistent,andaretheystructurallycomplete?
• RequirementsvalidaIonisdifficultfortworeasons:– Thefirstreasonisphilosophicalinnature,andconcernsthequesIonoftruth
andwhatisknowable.– Thesecondreasonissocial,andconcernsthedifficultyofreachingagreement
amongdifferentstakeholderswithconflicInggoals.
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Evolvingrequirements• Successfulsocwaresystemsalwaysevolveasthe
environmentinwhichthesesystemsoperatechangesandstakeholderrequirementschange.ThereforemanagingchangeisafundamentalacIvityinRE[9].
• ChangestorequirementsdocumentaIonneedtobemanaged.Minimally,thisinvolvesprovidingtechniquesandtoolsforconfiguraIonmanagementandversioncontrol[22],andexploiIngtraceabilitylinkstomonitorandcontroltheimpactofchangesindifferentpartsofthedocumentaIon.
• Finally,thedevelopmentofsocwaresystemproductfamilieshasbecomeanincreasinglyimportantformofdevelopmentacIvity.
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Integratedrequirementsengineering• REisamulI-disciplinaryacIvity,deployingavarietyoftechniquesandtools
atdifferentstagesofdevelopmentandfordifferentkindsofapplicaIondomains.MethodsprovideasystemaIcapproachtocombiningdifferenttechniquesandnotaIons,andmethodengineering[10]playsanimportantroleindesigningtheREprocesstobedeployedforaparIcularproblemordomain.MethodsprovideheurisIcsandguidelinesfortherequirementsengineertodeploytheappropriatenotaIonormodellingtechniqueatdifferentstagesoftheprocess.
• AvarietyofapproacheshavebeensuggestedtomanageandintegratedifferentREacIviIesandproducts.Jackson,forexample,usesproblemframestostructuredifferentkindsofelementaryandcompositeproblems[39].HisargumentisthatidenIfyingwell-understoodproblemsoffersthepossibilityofselecIngcorresponding,appropriate,well-understood,soluIons.
• AnalternaIveapproachtoorganising,selecIngandtailoringmulIplemethodsisthroughtheuseofmulIpleperspecIvesorviewsofrequirements[16;26].
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Decade1990-2000(beforepublicaIon)
During1990-2000,wecandiscerntheemergenceofthreeradicalnewideasthatchallengedandoverturnedtheorthodoxviewsofRE.Thesethreeideasarecloselyinterconnected:• TheideathatmodellingandanalysiscannotbeperformedadequatelyinisolaIon
fromtheorganisaIonalandsocialcontextinwhichanynewsystemwillhavetooperate.Thisviewemphasisedtheuseofcontextualisedenquirytechniques,includingethnomethodologyandparIcipantobservaIon[29;63].
• ThenoIonthatREshouldnotfocusonspecifyingthefuncIonalityofanewsystem,butinsteadshouldconcentrateonmodellingindicaIveandoptaIveproperIesoftheenvironment2[84].Onlybydescribingtheenvironment,andexpressingwhatthenewsystemmustachieveinthatenvironment,wecancapturethesystem’spurpose,andreasonaboutwhetheragivendesignwillmeetthatpurpose.ThisnoIonhasbeenaccompaniedbyashicinemphasisawayfrommodellinginformaIonflowandsystemstate,andtowardsmodellingstakeholders’goals[15]andscenariosthatillustratehowgoalsare(orcanbe)achieved[51].
• TheideathattheabempttobuildconsistentandcompleterequirementsmodelsisfuIle,andthatREhastotakeseriouslytheneedtoanalyseandresolveconflicIngrequirements,tosupportstakeholdernegoIaIon,andtoreasonwithmodelsthatcontaininconsistencies[28].
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N&E’sPredicIonfor2000-2010• DevelopmentofnewtechniquesforformallymodellingandanalysingproperIesoftheenvironment
• BridgingthegapbetweenrequirementselicitaIonapproachesbasedoncontextualenquiryandmoreformalspecificaIonandanalysistechniques.
• Richermodelsforcapturingandanalysingnon-funcIonalrequirements.
• BeberunderstandingoftheimpactofsocwarearchitecturalchoicesontheprioriIsaIonandevoluIonofrequirements.
• Reuseofrequirementsmodels.• MulIdisciplinarytrainingforrequirementspracIIoners.
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Hottopics• Scale• Security• Tolerance• IncreasedRelianceonEnvironment• Self-Management• GlobalizaIon• Methodologies,paberns,andtools• RequirementsReuse• EffecIvenessofREtechnologies
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Scale
• Largescaleandultra-largescalesystemsàneedtomanagetensofthousandsofrequirements
• Systemsofsystems• Cyber-physicalsystems• E.g.futureintelligenttransportaIon-managementsystems,criIcalinfrastructureprotecIonsystems(e.g.,systemsmanagingpowergrids,bridges,telecommunicaIonsystems),integratedhealth-caresystems,anddisaster-responsesystems
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Security• IdenIfyanddocumentpotenIalsecuritythreats:idenIfiesassets,idenIfiesvulnerabiliIesinthecontextofpotenIalthreats,andspecifiescountermeasurestoprotectagainstthesethreats
• E.g.inmisusecasesandtheirmiIgaIon• AnalternaIveapproachwouldtakeatop-downviewofsecurityrequirements,andbaserequirementsonorganizaIonalstructures,suchaslinesofauthority,“separaIonofduIes,delegaIon,roles,groups,”accesspolicies,andsoon
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Tolerance• SocwareisincreasinglyusedtoautomatecriIcalapplicaIonsand
services,suchastransportaIonvehiclesandsystems,financialdecisionsandtransacIons,medicalcare,militarycommandandcontrol,andsoon;inwhichsecurityandassurancerequirementsareparamount.
• However,giventhecomplexityofsuchsystems,withrespecttosize,decentralizeddecision-making,andvariability,theSEandREcommuniIesmayneedtosocentheirviewsandexpectaIonsforsecurityandcorrectness.
• SufficientCorrectness:Thedegreetowhichasystemmustbedependableinordertoservethepurposeitsuserintends,andtodosowellenoughtosa&sfythecurrentneedsandexpecta&onsofthoseusers.
• àfocusonrequirementsforacceptablebehaviorandonwhatitmeansforasystemtobe“healthy”
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Increasedrelianceonenvironment
• Cyber-physicalsystems(CPSs)areanewgeneraIonofengineeredsystemsinwhichcompuIngandcommunicaIonareIghtlycoupledwiththemonitoringandcontrolofenIIesinthephysicalworld
• Examplecyber-physicalsystemsincludeintelligenttransportaIonandvehiclesystems;automatedmanufacturing;criIcalinfrastructuremonitoring;disasterresponse;opImizaIonofenergyconsumpIon;smartwearableapreforhealthcare,personalsafety,andmedicalneeds;andefficientagriculture
• Toreasonaboutanintegratedsystem,itbecomesnecessarytoformalizetheproperIesoftheenvironmentswithwhichthesocwarewillinteroperate.
• àThereneedtobebebertechniquesforintegraIngmodelsoftheenvironment,interfacedevices,andsocwarecomponents.
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Selfmanagement• Growinginterestinself-managingsystems,inwhichthesocwaresystem
isawareofitscontextandisabletoreactandadapttochangesineitheritsenvironmentoritsrequirements–suchasamobiledevice,whoseavailableservicesvarywiththeuser’slocaIonandwiththelocalserviceprovider(s).
• Examplesofsuchsystemsincludeself-healingsystemsthatareabletorecoverdynamicallyfromsystemfailure,faults,errors,orsecuritybreaches;andself-op&mizingsystemsthatareabletoopImizetheirperformancedynamicallywithrespecttochangingoperaIonalprofiles.
• REchallenges:– IdenIfyingandspecifyingthresholdsforwhenthesys-temshouldadapt– Specifyingvariablesetsofrequirements– MatchingrequirementsalternaIvestorun-Imeneeds– IdenIfyingcorrectnesscriteriaforadapIvesystems– VerifyingmodelsofadapIvesystemsandtheirsetsofpossiblebehaviors– Monitoringthesystemandenvironment,againstthecurrentrequirements
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GlobalizaIon• GlobalsoEwaredevelopmentisanemergingparadigmshic
towardsgloballydistributeddevelopmentteams(exploita24-hourworkday,capitalizeonglobalresourcepools,de-creasecosts,andbegeographicallyclosertotheend-consumer).
• Downside:communicaIongaps• Challenges:
– 1.neworextendedREtechniquesareneededtosupportoutsourcingofdownstreamdevelopmenttasks,suchasdesign,coding,andtesIng.
– 2.toenableeffecIvedistributedRE,i.e.managedistributedrequirementselicitaIon,distributedmodeling,distributedrequirementsnegoIaIon,andthemanagementofdistributedteams
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Methodologies,Paberns,andTools
• ThetransferofREtechnologiesfromresearchintopracIcewouldbenefitfrombeberadviceonhowtoapplythetechnologiesmoresystemaIcally.
• Thegoalsofthistypeofengineering-styleresearcharetoimprovetheproducIvityoftherequirementsanalystandtoimprovethequalityoftheresulIngrequirementsarIfacts.
• Forexample,justaspa3ernshelptoeasethecreaIonoflogicexpressions,researchintoidiomsandpabernsforothermodelingproblemsandnotaIonswouldimprovetheproduc6vityofmodelers.
• Similarly,modelingconven6ons,methodologies,andstrategiesallhelptosimplifyREtechniquessothatthetechniquescanbeusedsuccessfullybytypicalpracIIoners.
• Becausepabernsandstrategiesare,orsuggest,parIalsoluIons,theyhelpalsotoimposesomelevelofuniformityandpredictabilityintheresulIngrequirementsdescripIons.
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Methodologies,Paberns,andTools
• DespitethesignificantadvancesthathavebeenmadeinrequirementsmodelingandnotaIons,therehasbeenlibleworkonhowtointerconnectvarioustypesofrequirementsmodels.
• Well-definedapproachestointerrelaIngrequirementsgoals,scenarios,data,funcIons,state-basedbehavior,andconstraintsareneededtoaddressthisfundamentalproblem.
• FurtherresearchisneededonhowtointegrateREtechnologies,sothatpracIIonersknowhowtoapplyindividualtechnologieseffecIvelyandsynergisIcally.
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RequirementsReuse
• AnotherapproachtomakingREtasksmoreprescripIveandsystemaIcwouldbetofacilitatethereuseofexisIngrequirementsarIfacts.Themoststrategicformofrequirementsreuseisproductlining,
• AkeyREchallengeforproduct-linedevelopmentincludesstrategicandeffecIvetechniquesforanalyzingdomains;idenIfyingopportuniIesforproductlining;andidenIfyingthescope,commonaliIes,andvariabiliIesofaproductline.
• Asecondchallengerelatestohowrequirementsforproductlinesaredocumentedàe.g.featuremodels.
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EffecIvenessofRETechnologies
• Lastly,theulImateimpactofREresearchdependsonhowrelevanttheresultsaretoindustry’sshort-andlong-termneeds.Sofar,therehasbeensurprisinglylibleevaluaIonastohowwellREresearchresultsaddressindustryproblems.
• PracIIonersneedhardevidencethatanewtechnologyiscost-effecIve,inordertojusIfytheoverhead,intrainingandinprocessdocumentaIon,ofchangingtheirdevelopmentprocesses.
• InparIcular,pracIIonerswouldbenefitgreatlyfromempiricalstudiesthatassessthecostsandbenefitsofusingproposedtechnologies,assessthescopeofproblemstowhichresearchresultscanfeasiblybeapplied,andcomparetheeffecIvenessofcompeIngtechnologies.
• Therehavebeenafewstudiesalongtheselines.àWhataretheproblemshereforthosestudies?
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EffecIvenessofRETechnologies
• Lastly,theulImateimpactofREresearchdependsonhowrelevanttheresultsaretoindustry’sshort-andlong-termneeds.Sofar,therehasbeensurprisinglylibleevaluaIonastohowwellREresearchresultsaddressindustryproblems.
• PracIIonersneedhardevidencethatanewtechnologyiscost-effecIve,inordertojusIfytheoverhead,intrainingandinprocessdocumentaIon,ofchangingtheirdevelopmentprocesses.
• InparIcular,pracIIonerswouldbenefitgreatlyfromempiricalstudiesthatassessthecostsandbenefitsofusingproposedtechnologies,assessthescopeofproblemstowhichresearchresultscanfeasiblybeapplied,andcomparetheeffecIvenessofcompeIngtechnologies.
• Therehavebeenafewstudiesalongtheselines.àWhataretheproblemshereforthosestudies?
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FiverecommendaIons…thattheREcommunitycouldtakeimmediateacIonon,tostartimprovingthematurityofcurrentrequirementstechnologies:• ResearchersshouldworkwithpracIIoners.• REresearchersshouldworkwithotherSEresearchersand
pracIIoners,toestablishstrongerlinksbetweentheirrespecIvearIfacts.
• REresearchersshouldnotneglectevaluaIonandempiricalresearch.
• IndustrialorganizaIonsshouldprovide(saniIzed)industrial-strengthprojectdatatoresearchers.
• REresearchersandpracIIoners,together,shouldestablishrepositoriesofREarIfacts.
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