Function Points

Function Points

• 1.
  FUNCTION POINTS WTF?
• 2.
  YOUR COMPANY ISA SOFTWARE COMPANYIGNORANCE STOP FEIGNING ! Is a website 'software'? Is an iPhone or iPad app 'software'? Is Rich Media 'software'? YES! Absolutely! No doubt about it! Your company definitely IS a software company Is your company a world-class, best-in-class Software Company? Do you know how much software you produce? Per year? Per Month? Per Day? How much software - exactly, specifically? How productive are you - exactly?
• 3.
  BEST IN CLASSSOFTWARE COMPANIES Best in Class Software Companies Have: ● higher productivity ● higher quality Best in Class ● small project growth rates ● 28% Requirements ● 36% Design ● less overtime ● 20% Coding ● 16% Testing ● less redundancy ● more specialization Worst In Class ● 11% Requirements ● software ● 16% Design measurement programs! ● 37% Coding ● 37% Testing
• 4.
  PRODUCTIVITY “Goods or servicesper unit of labor or expenses” Productivity = outputs/inputs Software Productivity = functionality/hours ● Unit cost of software goes up with size ● Marginal costs for software increase with size ● There are different costs for each component
• 5.
  MEASUREMENT ● Standard units ●Houses can be measured in square feet ● Software can be measured too ● Measuring things is repeatable ○ an inch today is an inch tomorrow ● Measuring eliminates wasteful guessing and introduces accurate and justifiable
• 6.
  LINES OF CODE ●Language dependent ● Skill dependent ● Unknown until written ● No Standards ● Function Points are better
• 7.
  FUNCTION POINTS ARESTANDARDIZED Large user group IFPUG - http://ifpug.org 1,200 members in 30 countries around the world ISO Standard IFPUG v4.3 is an ISO standard De-facto standard estimating packages: Cocomo II, Construx Estimate, etc. Certified Function Point Specialist official IFPUG certification test Counting Practices Manual official manual by IFPUG FP data repositories large repositories of data
• 8.
  HISTORY ● 1979 FPsintroduced by Alan Albrecht ● 1984 First FP guidelines ● 1986 First IFPUG Board of Directors ● 1994 CPM Release 4.02003ISO standard ● 2003 ISO standard ● Adoption rate is increasing
• 9.
  OVERVIEW ● Measured fromthe user's perspective ● Technology-independent ● Low cost (once the system is in place) ● Repeatable ● Works well with use cases ● Answers lots of questions ● Can be automated
• 10.
  TYPES OF COUNTS 1.Development ○ all phases through deployment ○ forms a baseline 2. Enhancement ○ in production, has a baseline ○ count the size of successive enhancements 3. Application ○ in production, no baseline ○ forms a baseline
• 11.
  BENEFITS AND USES ●Accurate and justifiable estimations of ○ Cost ○ Duration ○ Staffing ● Actionable productivity metrics, including ○ Defect rate ○ Cost per function point ○ Velocity (fp/hr) ● Competitive advantages ○ Fixed prices ○ Real data and facts to drive decisions
• 12.
  BENEFITS AND USES ●software sizing ● when and what to re-engineer ● communication ● test case estimation ● over-time reduction ● productivity ● project inventory ● scope creep ● estimates ● true cost ● repeatability ● contracts ● organization portfolio
• 13.
  APPLY THE DATA Given: ● a team of developers that average 18 FP/month (velocity) ● at an average cost of $5200/month per developer ● with requirements doc that contains 197 FP Derive: ● months of effort ○ 197 / 18 = 11 man-months ● cost ○ 11 x 5200 = 57,200 dollars ● duration ○ 2.5 x 2.2 = 5.5 months ● minimum duration ○ .75 x 2.2 = 1.65 months ● staff ○ square root of 11 = 3.3 developers ● and many, many more magical formulas!
• 14.
  WHEN NOT TOUSE ● when sizing maintenance efforts ○ detective work ○ maintenance productivity can vary ● when analyzing performance issues ○ may not be related to functionality ○ more likely about throughput & processing
• 15.
  CHALLENGES Must be anongoing corporate software metrics program initiative, not an afterthought or on-the-side pet project Must be systematized and well-managed in order to be accurate Counting requires special training and/or special software Usage of count data will challenge and transform existing management practices
• 16.
  TIP OF THEICEBERG