This example illustrate Application Count calculated from Development Project Count . The Application Count measures the functions provided to the users with the first installation of the software delivered when the development project is complete.
A Development Project Count can contain Elementar Processes with the Process Type conversion . Once you have created an Application Count from Development Project Count , the new Application Count does not contain the Elementar Processes with the Process Type conversion .
Application Function Point Calculation
This section provides the formulas to calculate the Application Count . There are two variations of this formula:
-
Formula to establish the initial function point count for an application.
-
Formula to re-establish the function point count for an application after an enhancement project has changed the application functionality.
Formula to Establish the Initial Count:
Use the formula in this section to establish the initial function point count for an application. Initially, the user is receiving new functionality. There are no changes to the existing functionality or deletions of obsolete or unneeded functionality. The Application Count does not include conversion requirements.
AFP = ADD * VAF
Where:
AFP is the initial application function point count.
ADD is the unadjusted function point count of those functions that were installed by the development project.
VAF is the value adjustment factor of the application.
Formula to Reflect Enhancement Projects
When an enhancement project is installed, the existing application function point count must be updated to reflect modifications to the application. The functionality for the application can be altered in one or more ways:
- Added (new) functionality increases the size of the application
- Changed functionality increases, decreases, or has no effect on the size of the application
- Deleted functionality decreases the application size
- Changes to the value adjustment factor increase or decrease the application size
Note: Because conversion functionality does not affect the application function point count, any conversion functionality associated with an enhancement project is omitted entirely from the application function point calculation. Use the following formula to calculate the application function point count after an enhancement project:
Use the following formula to calculate the application function point count after an enhancement project:
AFP = [(UFPB + ADD + CHGA) - (CHGB + DEL)] * VAFA
Where:
AFP is the application's adjusted function point count.
UFPB is the application's unadjusted function point count before the enhancement project begins.
Note: If this count is unavailable, it can be calculated using the formula UFBP = AFPB/VAFB ; where AFPB is the adjusted application function point count before the enhancement project. VAFB is the value adjustment factor of the application before the enhancement project.
ADD is the unadjusted function point count of those functions that were added by the enhancement project.
CHGA is the unadjusted function point count 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 count 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 count 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.
Refer to IFPUG document Function Point Counting Practices Manual for additional information about the function point analysis, or see at: IFPUG for additional information.