Determine which transactional functions will be modified and determine the impact factor

The transactional functions that change are identified and the size of each transaction after the change (the enhancement) is determined.

A transactional function is considered changed if it is altered in some way but retains the same name and purpose after enhancement as before enhancement. To determine the functional size of a transactional function after the change the same counting guidelines are used as for new-built systems, applying the standard FPA rules. A transactional function may be affected by changes to data functions. All transactional functions specified in the enhancement proposal and those affected by changes to data functions are included in the scope of the analysis.

This means that a transaction is counted when at least one of the following conditions is satisfied:

the transaction is identified in the enhancement proposal; or;
the transaction undergoes a function change as a consequence of other changes defined in the enhancement proposal.

In general, a transaction must be counted if the user can identify that the transaction has changed. This means that at least one of the following criteria is met:

a transaction is affected by a DET that is added, changed or deleted;
a transaction is affected by a Logical Data File (ILF or EIF) that is added, changed or deleted;
the user interface is functionally changed (for example, the composition of a screen or a report);
the business logic supporting a transaction is changed (for example, edit rules or calculations performed on the transaction data);
a cosmetic change visible in the user interface is made, for example:
- static data is changed or moved in a report or other media,
- a heading is replaced or changed in a report or on a screen

A change to the name of a DET is not regarded as a change in a transaction. The nature of the DET does not change if the name only is changed.

There are four steps to calculating the enhancement function point size of a change to a transaction:

Identify the DETs and FTRs used by the transaction.
Determine the percentages of DETs and FTRs changed as a result of the enhancement.
Determine the impact factor for the transaction.
Calculate the number of enhancement function points.