While doing research on projects counted in function points, the sample size was large enough (over 2000 projects) to allow me to compare the productivity of different project types. The QSM database uses these project categories:
- New Development (> 75% new functionality)
- Major Enhancement (25% - 75% new functionality)
- Minor Enhancement (5% - 25% new functionality)
- Conversion (< 5% new functionality)
I calculated the normalized PI’s for projects in each development classification compared to the QSM Business trend lines. The advantage of this is that it takes into consideration the impact of size and shows how the productivity of each project “application type” differs from the QSM Business IT average. The datasets included medium and high confidence IT projects completed since 2000. When I obtained the results, I went back over my selection process and calculations to make sure I hadn’t made a mistake. The numbers were that surprising. But, no, I hadn’t fat fingered anything (neither physically nor mentally). Average productivity for conversion projects was more than a standard deviation below the QSM Business IT average.