Additional FPA Guidelines

This page gives more information about additional Nesma guidelines, that fit within the general framework of the IFPUG FPA guidelines (IFPUG CPM 4.2), and tend to clarify them. That’s why they may be of great value to every FPA counter, also to those using the IFPUG rules. The counting rules of Nesma and IFPUG are the same (except a few minor differences).
Detailed information on these and other additional FPA guidelines you’ll find in the Nesma Counting Practices Manual CPM 2.1 (English language).

Methods for (very) early function point counting

The Nesma defines three types of function point counts:

  • detailed function point count (the usual one)
  • estimated function point count
  • indicative function point count

The methods estimated and indicative function point counts have been developed by NESMA to enable function point counting early in the system life cycle. The Nesma indicative function point count is well known in the world and is referred to as “the Dutch method”.
Detailed information about these early function point methods, including examples and statistical information about the accuracy of these methods, you’ll find here.

Dealing with physical media

The IFPUG CPM 4.2 unfortunately does not (yet) give concrete guidelines for this issue.
Without guidelines, even certified FPA counters have very different interpretations, and as a result, big differences in the determined number of function points for the application.

For the Nesma, the physical medium does not, in and of itself, add additional functionality. The same input read from different physical media is counted as only one external input, if the input data element types and the logical processing are the same. The same output written to different physical media is counted as only one external output (or external inquiry) when the logical layout and the logical processing are the same. The IFPUG has not made a clear statement about this in its Counting Practices Manual 4.2.

More information on dealing with physical media is available here.

Querying with several selection criteria (“and/or situations”)

The IFPUG CPM 4.2 unfortunately does not (yet) give concrete guidelines for this issue.
Without guidelines, even certified FPA counters have very different interpretations, and as a result, big differences in the determined number of function points for the application.

This is often an issue; e.g., a selection screen with state-id and surname. The user can enter one or both of these items in order to select customers (e.g., show me all customers in Washington DC).
Should each and every distinct “and/or situation” be considered a separate EO/EQ or should only one EO/EQ be counted?

The Nesma uses a go between:

“When the user has more options (i.e., an “and/or situation”), count the selections that mutually exclude each other. Each selection or combination of selections that exclude all others is counted separately”.

More information on querying with several selection criteria is available on another page.

Other additional Nesma Guidelines

The Nesma has developed counting guidelines on several other issues. Although relevant, the influence of these issues on a function point count is less, than the issues described above. All of these hints and guidelines may be found in the Counting Practices Manual of the Nesma (English language).

This is a summary of the other additional counting guidelines:

  • Guidelines for applying FPA in specific situations.
  • Guidelines for using FPA in the system life cycle.
  • Twenty general points of particular interest and guidelines when applying FPA, e.g.,
  • Counting on the basis of traditional design
  • Counting application packages
  • Counting from screens
  • Report generators and query facilities
  • Shared use of data
  • Guideline for counting combination effects with functions
  • Guidelines for determining when an external output must be considered unique
  • Guideline for output products in different languages
  • Many other additional hints, do’s and don’ts that may be used while counting function types.