Home // International Journal On Advances in Software, volume 13, numbers 3 and 4, 2020 // View article

A Large Scale Empirical Evaluation of the Accuracy of Function Points Estimation Methods

Authors:
Luigi Lavazza
Geng Liu

Keywords: Function Points; IFPUG; Function point Analy- sis; Functional Size Measurement; Functional Size Estimation; NESMA Estimated; NESMA Indicative; Early Size Estimation.

Abstract:
Functional size measures of software—especially Function Points—are widely used, because they provide an objective quantification of software size in the early stages of development, as soon as functional requirements have been analyzed and documented. Unfortunately, in some conditions, performing the standard Function Point Analysis process may be too long and expensive. Moreover, functional measures could be needed before functional requirements have been elicited completely and at the required detail level. To solve this problem, many methods have been invented and are being used to estimate the functional size based on incomplete or not fully detailed requirements. Using these methods involves a trade-off between ease and timeliness on one side and accuracy on the other side. In fact, estimates are always affected by some error; knowing the magnitude of estimation errors that characterize the estimates provided by a given method is of great importance to practitioners. This paper reports the results of an empirical study devoted to evaluate the accuracy of estimates provided by Function Points estimation methods. The results of the study show that some of the evaluated methods—including the Early & Quick Function Points, the ISBSG average and the NESMA estimated method)—provide estimates that are accurate enough for practical usage, while some other methods appear quite inaccurate.

Pages: 182 to 193

Copyright: Copyright (c) to authors, 2020. Used with permission.

Publication date: December 30, 2020

Published in: journal

ISSN: 1942-2628