Explain Function Point Metrics

  • 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 CommunicationF2. Distributed Data ProcessingF3. Performance
F4. Heavily Used ConfigurationF5. Transaction RoleF6. Online Data Entry
F7. End-User EfficiencyF8. Online UpdateF9. Complex Processing
F10. ReusabilityF11. Installation EaseF12. Operational Ease
F13. Multiple SitesF14. Facilitate Change

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