Can Function Points be Mapped to Object Points?

Ayman Issa¹, Mohammed Odeh1, and David Coward²

¹Centre for Complex Cooperative Systems, CEMS Faculty, University of the West of England, UK

²School of Computer Science, CEMS Faculty, University of the West of England, UK 

Abstract: Object points is a new software size metric that has emerged to cope with recent developments in software engineering, and to overcome the deficiencies of the traditional lines of code and function points size metrics. Moreover, object points has been utilized as the basis for several software cost estimation models with promising improvements in the accuracy of estimates. However, the infancy of the object points size metric means that there is a shortage of object points based software historical projects, on which to base the empirical validation of the new object points based software cost estimation models. Hence, the relationship between the extensively used function points and newly invented object points size metrics have been conceptualized and utilized in a novel forward approach to convert the function points projects data into their equivalent object points data. Empirical investigations of 66 function points projects have shown high correlation and significance, 88% and 0.33, respectively, between the resulting object points effort estimates and the actual function points effort. Furthermore, the resulting object points data have been utilized to model the embodied function points-object points relationship in two specialized productivity factors and function points type dependent linear models. The resulting models have shown high fitness, R2, values of 0.95, for both models.

Keywords: Software size metrics, function points, object points, software cost estimation.