Software Risk Management and the COCOMO ModelOutlineWhat is Software Risk Management?Risk of Delaying Risk Management: SoftwareSlide 5Risk of Delaying Risk Management: SystemsThe Fundamental Risk Management MetricPrioritizing Risks: Risk Exposure Risk Exposure = (Probability) (Loss of Utility)Risk Exposure Factors (Satellite Experiment Software)Risk Exposure Factors and Contours: Satellite Experiment SoftwareRisk Reduction Leverage (RRL) Equivalent to Return on InvestmentSlide 12Early Risk Resolution QuotesDay One Temptations to AvoidWaterfall Model Risk ProfileICM Risk ProfileThe ICM and Continuous Risk ManagementNature of FEDs and Anchor Point MilestonesProblems Encountered without FED: 15-Month Architecture Rework DelayProblems Avoidable with FEDSlide 21Slide 22Software Risk ManagementRisk Identification TechniquesTop 10 Risk Items: 1989 and 1995Example Risk-item Checklist: StaffingThe Top Ten Software Risk ItemsThe Top Ten Software Risk Items (Concluded)Network Schedule Risk AnalysisCost Risk Analysis: COCOMO IICOCOMO Baseline Overview ISlide 32Slide 33Slide 34Slide 35USC COCOMO II ModelTradeoffs Among Cost, Schedule, and Reliability: COCOMO IISlide 38Slide 39Slide 40Risk Management OptionsRisk Management PlansRisk Management Plan: Fault Tolerance PrototypingRisk Management Plan: Fault Tolerance Prototyping (concluded)Risk MonitoringProject Top 10 Risk Item List: Satellite Experiment SoftwareConclusionsUniversity of Southern CaliforniaCenter for Software Engineering C S E USCMarilee Wheaton, USC August 31, 2010Software Risk Management and the COCOMO ModelUniversity of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 2Outline•What is Software Risk Management?•When should you do it?–Continuously from Day One•How should you do it?–Risk Assessment•Cost risk assessment and COCOMO II–Risk Control•ConclusionsUniversity of Southern CaliforniaCenter for Software Engineering C S E USCWhat is Software Risk Management?•An approach for early identification and mitigation of critical project uncertainties–Learning early and cheaply–Narrowing the Cone of Uncertainty–Avoiding expensive late rework08/31/2010 ©USC-CSSE 3University of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 4Risk of Delaying Risk Management: SoftwarePhase in Which defect was fixed1020501002005001000Relative cost to fix defect215Requirements Design Code Development Acceptance Operation test testSmaller software projectsLarger software projects• Median (TRW survey) 80% 20%SAFEGUARDGTEIBM-SSD• • • • • •University of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 5Steeper Cost-to-fix for High-Risk Elements01020304050607080901000 10 20 30 40 50 60 70 80 90 100% of Software Problem Reports (SPR’s)TRW Project A373 SPR’sTRW Project B1005 SPR’s% ofCosttoFixSPR’sMajor Rework Sources:Off-Nominal Architecture-BreakersA - Network FailoverB - Extra-Long MessagesUniversity of Southern CaliforniaCenter for Software Engineering C S E USCRisk of Delaying Risk Management: Systems—Blanchard- Fabrycky, 1998Detail DesignandDevelopment100255075Conceptual-PreliminaryDesignConstructionand/orProductionSystem Use, Phaseout,and DisposalNEED%Commitment to Technology,Configuration, Performance, Cost, etc.Cost IncurredSystem-Specific KnowledgeEase of Change(Cone of Uncertainty)University of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 7The Fundamental Risk Management Metric•Risk Exposure RE = Prob (Loss) * Size (Loss)–“Loss” – of stakeholders’ value– financial; reputation; quality of service, …•For multiple sources of loss:sourcesRE =  [Prob (Loss) * Size (Loss)]sourceUniversity of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 8Prioritizing Risks: Risk ExposureRisk Exposure = (Probability) (Loss of Utility)Risk ProbabilityHighLowCheckUtility - Loss EstimateLittleRiskLowLoss of UtilityHighCheckProbabilityEstimateMajorRiskUniversity of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 9Risk Exposure Factors(Satellite Experiment Software)Unsatisfactory Outcome (UO)Prob (UO)Loss (UO)Risk ExposureA. S/ W error kills experimentB. S/ W error loses key dataC. Fault tolerance features cause unacceptable performanceD. Monitoring software reports unsafe condition as safeE. Monitoring software reports safe condition as unsafeF. Hardware delay causes schedule overrunG. Data reduction software errors cause extra workH. Poor user interface causes inefficient operationI. Processor memory insufficientJ. DBMS software loses derived data3 - 53 - 5 4 - 855686121087934157230 - 5024 - 4028 - 5645152483074University of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 10Risk Exposure Factors and Contours: Satellite Experiment SoftwareUniversity of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 11Risk Reduction Leverage (RRL)Equivalent to Return on InvestmentRRL = REBEFORE - REAFTERRISK REDUCTION COST· Spacecraft ExampleLOSS (UO)PROB (UO)REBBLONG DURATIONTEST$20M0.2$4MFAILURE MODETESTS$20M0.2$4MPROB (UO)REAA0.05$1M0.07$1.4MCOST $2M $0.26MRRL4-12= 1.54- 1.40.26= 10University of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 12Outline•What is Software Risk Management?•When should you do it?–Continuously from Day One•How should you do it?–Risk Assessment•Cost risk assessment and COCOMO II–Risk Control•ConclusionsUniversity of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 13Early Risk Resolution Quotes“In architecting a new software program, all the serious mistakes are made on the first day.” Robert Spinrad, VP-Xerox, 1988“If you don’t actively attack the risks, the risks will actively attack you.”Tom Gilb, 1988University of Southern CaliforniaCenter for Software Engineering C S E USC08/31/2010 ©USC-CSSE 14Day One Temptations to Avoid •It’s too early to think about risks. We need to:–Finalize the requirements–Maximize our piece of the pie–Converge on the risk management organization, forms, tools, and procedures. Don’t put the cart before the horse. •The real horse is the risks, and it’s leaving