- Function point metrics provide a standardized method for measuring the various functions of a software application
- Function point metrics, measure functionality from the user’s point of view, that is, on the basis of what the user requests and receives in return
Information domain values:
- Number of user inputs – Distinct input from user
- Number of user outputs – Reports, screens, error messages,
- Number of user inquiries – On line input that generates some result
- Number of files – Logical file (database)
- Number of external interfaces – Data files/connections as interface to other systems Formula to count FP is
FP = Total Count * [0.65 + 0.01*∑(Fi)]
Where, Total count is all the counts times a weighting factor that is determined for each organization via empirical data. Fi (i=1 to 14) are complexity adjustment values. Value Adjustment Factors (Fi):
| F1. Data Communication | F2. Distributed Data Processing | F3. Performance |
| F4. Heavily Used Configuration | F5. Transaction Role | F6. Online Data Entry |
| F7. End-User Efficiency | F8. Online Update | F9. Complex Processing |
| F10. Reusability | F11. Installation Ease | F12. Operational Ease |
| F13. Multiple Sites | F14. Facilitate Change |