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CornellUniversity ComputingandInformationScience
CS5150SoftwareEngineering4.FeasibilityStudies
WilliamY.Arms
FeasibilityStudy
Afeasibilitystudyisastudymadebeforecommittingtoaproject. Afeasibilitystudyleadstoadecision: •goahead •donotgoahead •thinkagain Inproductionprojects,thefeasibilitystudyoftenleadstoabudgetrequest. Afeasibilitystudymaybeintheformofaproposal.
WhyareFeasibilityStudiesDifficult?
Uncertainty •Clientsmaybeunsureofthescopeoftheproject.•Benefitsareusuallyveryhardtoquantify. •Approachisusuallyill-defined.Estimatesofresourcesandtimetableareveryrough.
•Organizationalchangesmaybeneeded. Therefore,feasibilitystudiesrelyheavilyonthejudgmentofexperiencedpeople. Mistakesmadeatthebeginningofaprojectarethemostdifficulttocorrect.
WhyareFeasibilityStudiesDifficult?
Advocacy •Advocacyisneededtobuildenthusiasmforaproject:toconvinceanorganizationtoundertakeanexpensive,complexprojectwithmanyrisks.
•Enthusiasmisgood,butenthusiastsusuallyemphasizepotentialbenefitsanddownplayrisks.
Peoplecarryingoutthefeasibilitystudyandmakingthedecisionoftenhaveavestedinterestintheprojectgoingahead,e.g.,financialgain,careerdevelopment. CS5150FeasibilityStudy ItispossiblethatyourCS5150feasibilitystudymayrecommendnotgoingaheadwithaproject.
TheDecisionMaker'sViewpoint
Thefeasibilitystudymakesrecommendations. Seniormember(s)oftheclient’sorganizationdecidewhethertobeginamajorsoftwareproject.Whatinformationdotheyneeded? Client:Whoisthisprojectfor? Scope:Whataretheboundariesoftheproject? Benefits:Whatarethebenefits?Cantheybequantified?Ifthesoftwareisaproduct,whataretheforecastsoflikelysales? Technical:Istheprojectpossible?Isthereatleastonetechnicalwaytocarryouttheproject?Resources:Whataretheestimatesofstaff,time,equipment,etc.? Alternatives:Whataretheoptionsiftheprojectisnotdone?
WherearetheRisks?CantheybeMinimized?
Technicalrisks•Theremustbeanoutlineplanwitharoughtimetableandstaffallocation. •Theplanmusthaveaverylargemarginforcontingencies.(Projectstypicallyrequiretwicethestaffand/ortimeenvisagedinthefeasibilityplan.)
External •Everysysteminteractswithothers.Aretheotherscommittedtothenecessaryefforts(e.g.,potentialusersandcustomers)?
•Wherearetheexternalpressuresandobstacles?
OrganizationalFeasibility
Amajorcomputersystemmakesdemandsonanorganization: • Doestheorganizationhavethemanagementexpertise? • Doestheorganizationhavethetechnicalexpertise?Eveniftheworkiscarriedoutbyacontractor,theorganizationneedsexpertisetooverseethework.
• Istheorganizationcommittedtothechangesinpersonnel,workflow,etc.? Example Copyrightdepositsystem:clericalworkflow.
Example1:U.S.GovernmentAgency(DecisionbeforeFeasibilityStudy)
OutlineDescription AU.S.governmentagency,whichmanageshugenumbersofdocumentsandotherrecords,wishestomovefromapaperbasedapproachtoasystemthatcanmanagedigitaldocuments.
Example1:Chronology
• AcomputingcenteratUniversitySdevelopedaprototypesystemtodemonstratetechnology.
• FundswereapprovedbyCongressto"procure"amajorcomputersystem. • Anexternalfeasibilitystudywascommissionedtoreportonthetechnical
approachtobefollowedandtheresultsoftheUniversitySprototype(technicalfeasibility).
Problems Thedecisiontogoaheadwasmadeandthebudgetwasapprovedbeforethefeasibilitystudywasbegun.
Thefeasibilitystudylookedatonlythetechnicalaspects.
Example1:Problems
Organizational: •Agencyseniormanagementlackedtheexperiencetoleadaverylargeprojectthatwillcompletelychangetheagency.
•Nothoughtwasgiventotheworkflowandjobchangesthatwouldaffectalmosteverymemberofstaff.
Preparation: •Nopreliminarystudywasmadeofvolumesorkindsofdata;norofthecomplexpoliciesforaccess(e.g.,privacy,classifiedinformation).
Requirements:•Therequirementswerecomplexandonlypartiallyunderstood.Majorchangeswereinevitableevenafterthesystemwentintoproductionwithrealusers.
Example1:Dilemma
Theexternalfeasibilitystudywaspaidforbyagencyandrestrictedtotechnicalconsiderations,butnoted: •Asuccessfulimplementationneededfundamentalchangesattheseniormanagementlevel.
•Aphasedapproach,usingiterativerefinementovermanyyears,mightpossiblywork,butonlyaftertheorganizationalproblemsareaddressed.
BUT... TheagencydidnotwanttoreturnmoneytoCongress. Theagency,adoptedapurewaterfallmodel,putoutaRequestforProposalfortherequirements,andplacedamajorcontractwithasoftwarehouse. Thisishowdisastersaremade.
FeasibilityStudy:Scope
Scopeexpressestheboundariesofthesystem: • Itwillhavealistofincludedfunctions • Itwillhavealistofexcludedfunctions • Itwillhavealistofdependencies • Itwillhavealistofcurrentsystemstobereplaced Confusionoverscopeisacommonreasonforclientstobedissatisfiedwithasystem."Isthatallyouplannedtodo?""ButIassumedthatyouweregoingtodoxyz.""Ican'tusethesystemwithoutabc."
Example2:AGovernmentRepository(ConfusionoverScope)
•Agovernmentorganization,L,requireda"repositorysystem"tostoreandmakeaccessibleverylargeamountsofhighlyvariedmaterialoverlongperiodsoftime.
•Anoutsideorganization,C,builtarepositorysystemtostoreandmanipulatecomplexdigitalmaterial.
BUT...•Nobodybuiltthesub-systemsneededtoorganize,validate,andtoloadmaterialintotherepository.
•Lexpectedtherepositorysystemtoincludethesesub-systems.Cconsideredthesub-systemsseparatefromtherepositorysystem.
Agoodfeasibilitystudywouldhaveseenthisconfusion.
FeasibilityStudy:Benefits
Whyisthisprojectproposed?Canyouquantifythebenefits? Organizationbenefits •Createamarketableproduct •Improvetheefficiencyofanorganization(e.g.,savestaff) •Controlasystemthatistoocomplextocontrolmanually •Neworimprovedservice(e.g.,fasterresponsetocustomers) •Safetyorsecurity Professionalbenefitsarenotthereasonfordoingaproject
FeasibilityStudy:Technical
Afeasibilitystudyneedstodemonstratethattheproposedsystemistechnicallyfeasible.Thisrequires: •anoutlineoftherequirements •apossiblesystemdesign(e.g.,database,distributed,etc.) •possiblechoicesofsoftwaretobeacquiredordeveloped •estimatesofnumbersofusers,data,transactions,etc. Theseroughnumbersarepartoftheprovisionalplanthatisusedtoestimatethestaffing,timetable,equipmentneeds,etc. Thetechnicalapproachactuallyfollowedmaybeverydifferent.
FeasibilityStudy:PlanningandResources
Thefeasibilitystudymustincludeanoutlineplan: •Estimatethestaffingandequipmentneeds,andthepreliminarytimetable
•Identifymajormilestonesanddecisionpoints •Identifyinteractionswithanddependencesonexternalsystems •Provideapreliminarylistofdeliverablesanddeliverydates ThereisaseparatelectureaboutProjectManagement.
FeasibilityStudy:AlternativesandRisks
Afeasibilitystudyshouldidentifyrisksandalternatives.Risks • Whatcangowrong? • Howwillprogressbemonitoredandproblemsidentified(visibility)? • Whatarethefallbackoptions?Alternatives• Continuewithcurrentsystem,enhanceit,orcreatenewone? • Developin-house,orcontractout?(Howwillacontractbemanaged?) • Phasesofdeliveryandpossiblepointsforrevisingplan.
TechniquesforFeasibilityStudies
Thehighestpriorityistoensurethattheclientanddevelopmentteamhavethesameunderstandingofthegoalsofthesystem. Forthedevelopmentteamtounderstandthegoals: •Interviewswithclientandthestaffoftheclient’sorganization
•Reviewofexistingsystems(includingcompetitors’) Fortheclienttoappreciatetheproposedsystem: •Demonstrationofkeyfeaturesorsimilarsystems •Mock-upofuserinterfaces •Walkthroughtypicaltransactionsorinteractions
TechniquesforFeasibilityStudies
Outlinebudget: •npeopleformmonthsat$xpermonth •equipment,buildings,etc. •contingency(atleast50%isneeded) Phases/milestones: •specifydeliverablesandapproximatedates •plannedreleases
FeasibilityStudy:Decision
Differentorganizationsandseniormanagershavedifferentstylesforfeasibilitystudies,e.g.,somedecisionmakers: •Monitortheteamandtheprocess •Relyondetailedreadingofawrittenreport •Relyonface-to-facequestioningofknowledgeablepeople Buttheymustunderstandthedecision.
FeasibilityReport
Afeasibilitystudyshouldhaveawrittenreport.Itshouldbeawellwritten,wellpresenteddocument. •Forageneralaudience:client,financialmanagement, technicalmanagement,etc. •Shortenoughthateverybodyreadsit. •Longenoughthatnoimportanttopicsareskipped. •Detailscanbeincludedinsupportingdocuments. Areportthatisnotreadandunderstoodisuseless.
CS5150:FeasibilityReports
TwoexamplesofgoodCS5150feasibilityreportsfrompreviousyearsareonthewebsite,withthepermissionofthestudents.TheyarelinkedfromtheReportssectionontheAssignmentspage.
CS5150:FeasibilityReport
SpecificRequirementsfortheFeasibilityReport • Outlineplan,showingprincipalactivitiesandmilestones(seethelectureonProjectManagement).
• DiscussionofBusinessConsiderations(seeProjectspageonthecoursewebsiteandthelectureonLegalAspectsofSoftwareDevelopment).
• Riskanalysis.Whatcangowrong?Whatisyourfallbackplan?
CS5150:Challenges
Team:Howmanyhoursperweek?Whatskillsdopeoplehave? Time:Mustbecompletedbyendofsemester,includingoperationalsystem,documentation,presentation Equipmentandsoftware:Whatspecialneedsarethere? Client:Willtheclientbesufficientlyavailableandabletohelp? Start-uptime.Creatingateam,schedulingmeetings,acquiringsoftware,learningnewsystems,... Businessconsiderations.Licenses,trade-secrets,... Tooambitious.Nothingtoshowattheendofthesemester... Whatelse?
CS5150:HowtoMinimizeRisk?
Techniquesformanagingrisk•Severaltargetlevelsoffunctionality: required,desirable,optionalphases•Visiblesoftwareprocess:intermediatedeliverables•Goodcommunicationwithintheteam,withtheclientandwiththeTeachingAssistant(s)
•WelldefineddevelopmentprocessGoodprocessesleadtogoodsoftware
Goodprocessesreducerisk
CS5150FeasibilityStudies:Reports
Appointateammembertoreadandedittheentirereport. Content •Ifdifferentauthorswritedifferentsectionsofthereportaretheyconsistent?E.g.,dothescope,requirements,andplanagreeonwhatistobedone?
Style •Isthetextcomprehensible?Doesthereportusejargonthatisnotcleartotheclient?
•Ifpossible,haveanativeEnglishspeakerdothefinalediting.
CS5150FeasibilityStudies:CommonProblems
Thepurposeofafeasiblestudyistoestablishifaprojectisfeasible,atreasonablecost,withintheplannedperiod. Thereportshouldconcludewithrecommendationsaboutwhethertoproceed,butthefinaldecisionismadejointlybytheclientandthedevelopmentteam. Inpreviousyears,manyreportshavehadthefollowingproblems: •Thereportisvagueaboutthescope.Withoutacleardefinitionofscope,itisnotclearthattheprojectisfeasible.
•Theplandoesnotdescribetheactivitiesinenoughdetailtoestimatetheeffortconvincingly.
•Theprojectsistooambitious.Thereportneedstodescribehowwillyoumonitortheprogressandadjustthescopeifnecessary.