IFPUG 4.2 and 4.3 Conform

Function Point Modeler™ is a IFPUG 4.x conform Function Point Modeling tool. It includes formulas to calculate all the three types of function point counts—development project, enhancement project, and application according to CPM 4.2 and 4.3 .

Development ProjectCount

DFP = (UFP + CFP) * VAF

• DFP is the development project function point count
• UFP is the unadjusted function point count for the functions that will be available after installation
• CFP is the unadjusted function points added by the conversion unadjusted function point count
• VAF is the value adjustment factor

Application Count

After software installation, the application count is calculated using components of the development project count. The application function does not include any conversion functionality (CFP).

AFP = UFP * VAF

• AFP is the initial application function point count.
• UFP is the unadjusted function point count for the functions that will be available after installation
• VAF is the value adjustment factor

Enhancement Project Count

The enhancement project function point calculation consists of three components of functionality:
• Application functionality included in the user requirements for the project
• Conversion functionality included in the user requirements for the project
• Application value adjustment factor

EFP = [(ADD + CHGA + CFP) * VAFA] + (DEL* VAFB)

• EFP is the enhancement project function point .
• ADD is the unadjusted function point of those functions that were or will be added by the enhancement project.
• CHGA is the unadjusted function point of those functions that were or will be modified by the enhancement project. This number reflects the size of the functions after the modifications.
• CFP is the function point count of those functions added by the conversion
• VAFA is the value adjustment factor of the application after the enhancement project is complete.
• DEL is the unadjusted function point of those functions that were or will be deleted by the enhancement project.
• VAFB is the value adjustment factor of the application before the enhancement project begins.

Application Function Point Count After Enhancement Project Function Point Count

When an enhancement project is installed, the application function point must be updated to reflect changes in the application's functionality. Use the following formula to calculate the application function point after an enhancement project:

AFP = [(UFPB + ADD + CHGA) - (CHGB + DEL)] * VAFA

• AFP is the application's adjusted function point .
• UFPB is the application's unadjusted function point before the enhancement project begins.
• ADD is the unadjusted function point of those functions that were added by the enhancement project.
• CHGA is the unadjusted function point of those functions that were changed by the enhancement project. This number reflects the size of the functions after the changes.
• CHGB is the unadjusted function point of those functions that were changed by the enhancement project. This number reflects the size of the functions before the changes were made.
• DEL is the unadjusted function point of those functions that were deleted by the enhancement project.
• VAFA is the value adjustment factor of the application after the enhancement project is complete.