Umbrella standard for FPA standards
This page provides you with information about the international standard for functional sizing. This standard is more a reference framework than a concrete FPA-like method. That’s why ISO calls the methodology FSM: Functional Size Measurement.
Within this reference framework meanwhile FPA methods have been certified by ISO as official ISO standard, among them Nesma, IFPUG and Cosmic.
Below you’ll find an article by Francois Collier (chair of ISO SC7) that sketches the path towards the FSM standard and the recognition of FPA methods.
The functional size measurement family of standards is an example of the optimal use of the JTC 1 standardization process.
One of the many challenges for software developers products has been to find methods to properly estimate effort and time required for the development of a software product from the requirements. To address this issue, Allan Albrecht of IBM developed in the late 1970 a measurement approach called Function Point Analysis (FPA) that quantifies the functions contained within software in terms that are meaningful to the software users.
With time, as it became more popular, FPA evolved and some variations were developed. To address this issue, ISO/IEC JTC 1/SC7 decided in 1993 to initiate work in functional size measurement (FSM). A working group (WG12) was put together with representation from 12 countries and also from the principal FSM methods developing user groups. These were the International Function Point Users Group (IFPUG), the Common Software Measurement International Consortium (COSMIC), UK Software Metrics Association (UKSMA) and Netherlands Software Metrics Association (Nesma).
The strategy that was followed by the working group was to first develop a series of generic standards and guidelines on FSM, the 14143 series of standards. This set of standards was developed using the normal consensus building ISO process. Once these standards were published, the established methods standards setting organizations were invited to use the JTC1 PAS process to get ISO recognition, an invitation that IFPUG (ISO/IEC 20926), UKSMA (ISO/IEC 20968) and NESMA (ISO/IEC 24570) accepted. For the COSMIC (ISO/IEC 19761) standard, the normal ISO process was followed.
The outcome of this work is that all four major FSM methods now conform to a minimal set of minimal requirements set by ISO/IEC standards, and that they are all now also ISO/IEC standards.
Nesma FPA recognised by ISO
The NESMA-FPA-methodology has been certified by ISO as an official ISO standard. The basis for the standard is the NESMA FPA Counting Practices Manual. The standard is named NESMA ISO/IEC 24570.
The complete name of the standard is:
ISO/IEC IS 24570 Software Engineering – NESMA functional size measurement method version 2.1 – Definitions and counting guidelines for the application of Function Point Analysis
This is a success for Nesma, and a clear sign of international recognition. The ISO-certification may be seen as a guarantee for the quality of the FPA-methodology.