Changing from FPA to COSMIC

A transition framework

Heeringen, H.S. van

Many organizations are considering to change their functional size measurement method
from FPA to COSMIC1, mainly because of the fact that more and more projects become ‘less
sizeable’ with FPA. A lot of them refrain from doing so, because they fear to loose their
experience base based on function points. This paper presents a framework to successfully
transform a functional size measurement method from FPA to COSMIC. The purpose of this
paper is to offer some guidance to make it easier for organizations to transfer to COSMIC,
while keeping the experience data that has been gathered with FPA. It continues on earlier
work of Vogelezang and Lesterhuis (2003) and Desharnais, Abran & Cuadrado (2006).
For this paper, 26 projects have been sized with both methods. An analysis will be
presented to see if there are differences between measurements carried out in COSMIC and
FPA. Furthermore, an analysis will be presented about the outliers (the data points that do
not correlate with the regression formula).