FPA and Maintenance

[Ton Dekkers]

At the time of publication of the current version of this method, in the Nesma board there was some discussion on the scientific evidence to support this approach. And although the determined size is called Maintenance Function Points, in practice this would be called also Function Points. All this could lead to miscommunication and confusion and this is something we really need to avoid, especially in contractual situations. This is the main reason for the disclaimer in the document and the website.

In the discussion about the approach also the argument was made that including productivity factors (introduced via the impact factor) into the size measurement would cease the method not to be compliant anymore with ISO 14143. Or more concrete with that the approach would also be not compliant with the official Nesma standard.

The board wanted to start a new Working Group (WG) to validate the approach but at that time there was no interest. As all WG activities are based on voluntary participation this validation is not forced by Nesma and therefore this working group never materialized. As we see potential value, Nesma offers the approach however with a disclaimer and we are very careful in promoting the approach.

Nevertheless I know the approach is used more widely, although there is limited to no official feedback on the application of the method. Interest in the approach is known based on the large number of downloads of the document and the available translations. I’m personal aware of contracts referring to the approach.

My personal opinion is that it makes sense to differentiate the impact of enhancements in an objective way. And the approach is well defined and basically aligned with the ISO standard 14143. Whether the “new” productivity factor can be used depends on the situation and has to be considered carefully. But that has to be done anyway, also when applying for new development projects only.

Nesma encourages people that use the approach to give feedback and/or to discuss their experiences, for instance through the Nesma forum. In case of increased interest, it would be possible to investigate if a new working group can be started after all. There is no reason why this can’t be an international working group, so you may be interested to join

[Frank Vogelezang]

In the projects I have worked with I have always wondered whether the differentiation of the impact of different enhancements really made sense. Therefore I have done an analysis of a number of enhancements. The results were published at the IWSM Mensura 2014 conference in Rotterdam. The results indicate that for this contract it did not add value to use enhancement function points. Whether this conclusion can be generalized I cannot tell, based on 25 data points in one environment.

The paper can be downloaded from IEEE Xplore or my LinkedIN profile.

[Ton Dekkers]

Someone made a remark about the use of “new productivity factor” . It’s confusing and should have been “new productity figure”, the effort needed related to produce 1 fp in new development.

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