CAST Webinar - Capers Jones on Function Points

Software Productivity Research LLCUsing Function Point MetricsFor Software Economic StudiesCapers Jones, Chief Scientist EmeritusEmail: CJonesiii@cs.comWeb://www.spr.comEmail: CJonesiii@cs.comJanuary 27, 2010FPEcon\1Copyright © 2009. All Rights Reserved.REASONS FOR SUCCESS OF FUNCTION POINTS•Function points match standard economic definitionsfor productivity analysis:“Goods or services produced per unitof labor or expense.”•Function points do not distort quality and productivityas do “Lines of Code” or LOC metrics.•Function points support activity-based cost analysis,baselines, benchmarks, quality, cost, and value studies.FPEcon\2Copyright © 2009. All Rights Reserved.REASONS FOR SUCCESS OF FUNCTION POINTS•Lines of code metrics penalize high-level programminglanguages.• If used for economic studies with more than one languageLOC metrics should be considered professional malpractice.• Cost per defect metrics penalize quality and make buggysoftware look best. For quality economic studies cost perdefect metrics are invalid. Function points are best.• Function point metrics have the widest range of useof any software metric in history: they work for botheconomic and quality analyses.FPEcon\3Copyright © 2009. All Rights Reserved.MAJOR FUNCTION POINT USES CIRCA 2010• Function points are now a standard sizing metric.• Function points are now a standard productivity metric.• Function points are now a powerful quality metric.• Function points are now a powerful schedule metric.• Function points are now a powerful staffing metric.• Function points are now used in software litigation.• Function points are now used for outsource contracts.• Function points can be used for cost analysis (with care).• Function points can be used for value analysis (with care.)FPEcon\4Copyright © 2009. All Rights Reserved.NEW FUNCTION POINT USES CIRCA 2010• Function points used for portfolio analysis.• Function points used for backlog analysis.• Function points used for risk analysis.• Function points used for real-time requirements changes.• Function points used for software usage studies.• Function points used for delivery analysis.• Function points used for COTS analysis.• Function points used for occupation group analysis.• Function points used for maintenance analysis.FPEcon\5Copyright © 2009. All Rights Reserved.FUNCTION POINTS FROM 2010 TO 2020• Resolve functional vs. technical requirements issues.• Resolve overhead, inflation, and cost issues.• Resolve global variations in work hours and work days.• Resolve issue of > 90 software occupation groups• Produce conversion rules for function point variations.• Improve cost, speed, and timing of initial sizing.• Develop and certify “micro function points.”• Expand benchmarks to > 25,000 projects.FPEcon\6Copyright © 2009. All Rights Reserved.INDUSTRY EVOLUTION CIRCA 2010-2020• Moving from software development to software delivery• Development rates < 25 function points per staff month• Delivery rates > 500 function points per staff month• Delivery issues: quality, security, band width• Delivery methods:Service Oriented Architecture (SOA)Software as a Service (SaaS)Commercial reusable librariesFPEcon\7Copyright © 2009. All Rights Reserved.FUNCTION POINT EVOLUTION CIRCA 2010-2020• Measure delivered features as well as development.• Measure and catalog reusable features.• Measure deployment, installation, and usage.• Measure quality and security.• New measurements needed:Sizes of reusable componentsQuality, security of reusable componentsSizes of delivered applicationsDeployment and usage of delivered applicationsFPEcon\8Copyright © 2009. All Rights Reserved.MIGRATION TO FUNCTIONAL METRICS100%Other Metrics (Functional)90%Measurements Based onIFPUG Function Points80%Measurements Based on70%Lines of Source Code LOC usage is60%Professional Malpractice 50%40%No Measurements At All30%20%Expansion of function point metrics10%Is urgently needed!0%1980198519901995200020052010Calendar YearFPEcon\9Copyright © 2009. All Rights Reserved.FUNCTIONAL METRICS IN INDUSTRYPRODUCTIONVALUE ANALYSISSTUDIESAND USAGE STUDIESIndividualOrganizational EnterpriseSoftwareSoftware Users & ValueUsers & ValueUsage & ValueProjectsPortfolios30,000 function points100 to 100,000Managers500,000 functionfunction pointspointsA90,000 function pointsEngineeringEngineers15,000 function points1,500,000 toSalesmen15,000,000B1,000,000 tofunction20,000,000pointsMarketing & SalesfunctionpointsAdministratorsCSupervisors• SizingManufacturing• Size• Productivity• Replacement CostPurchasing• Quality• Productivity• Schedules• Quality• CostsFPEcon\10Copyright © 2009. All Rights Reserved.