FPA Counting Guidelines of Nesma and IFPUG
When the Nesma issued the first version of its manual Definitions And Counting Guidelines For The Application Of Function Point Analysis in 1990, it assumed the principles of the IFPUG Counting Practices Manual (IFPUG CPM 2.0) that were valid at the time.
In those days, FPA was particularly applied to measure productivity and, therefore, people counted after the fact; i.e., on the basis of an application already built. Quite naturally, this was the departure point of the counting guidelines for IFPUG CPM 2.0. The Nesma, however, also wanted to use FPA for budgeting purposes and, therefore, wanted to count beforehand on the basis of an application’s functionality. In order to do this, it adapted a number of counting guidelines so they could be applied to logical models. This inevitably led to a number of differences in how the Nesma and the IFPUG counted function points in those days.
With the publication of IFPUG CPM 4.0(1994), the IFPUG also began to count function points on the basis of functionality and to assert that FPA counting must be independent of implementation. Owing to this change in philosophy, and to the intensive cooperation between the Nesma and the IFPUG the counting guidelines of the NESMA and the IFPUG continuously came closer and closer.
With the publication of IFPUG CPM 4.1 (1999) the FPA counting guidelines became the same, except a few guidelines. With the publication of IFPUG CPM 4.2 (2004) the last major differences between IFPUG and NESMA disappeared.
Differences between IFPUG FPA and Nesma FPA
Both the Nesma and the Ifpug now use the same philosophy, the same concepts and terms, and the same rules and guidelines within FPA.
For an actual insight in the remaining (minor) differences please review the document: FPA according to Nesma and IFPUG – the present situation
This document is updated on a regular basis.
Additional FPA Guidelines: Counting Issues made more concrete
Although there are no major differences remaining between IFPUG FPA and Nesma FPA, Nesma published some concrete, operational guidelines on complex counting issues for helping counters. So far, the IFPUG has not (yet) provided specific guidelines on these issues, or to a lesser degree. These additional FPA guidelines fit within the general IFPUG guidelines; they just tend to clarify or interpret the IFPUG guidelines. That’s why these guidelines are also applicable for those FPA counters using the IFPUG Counting Practices Manual.
This additional FPA guidelines are relevant to every function point analyst. They are all covered in detail by the Nesma CPM. If you would like to get an impression of the topics covered by the Nesma Counting Practices Manual, you may review the table of contents of Nesma CPM.