Analyzing the relationship between project productivity and environment factors in the use case points method

Abstract

Project productivity is a key factor for producing effort estimates from use case points (UCP), especially when the historical dataset is absent. The first versions of UCP effort estimation models used a fixed number or very limited numbers of productivity ratios for all new projects.These approaches have not been well examined over a large number of projects, so the validity of these studies was a matter for criticism. The newly available large software datasets allow us to perform further research on the usefulness of productivity for effort estimation of software development. Specifically, we studied the relationship between project productivity and UCP environmental factors, as they have a significant impact on the amount of productivity needed for a software project. Therefore, we designed 4 studies, using various classification and regression methods, to examine the usefulness of that relationship and its impact on UCP effort estimation. The results we obtained are encouraging and show potential improvement in effort estimation. Furthermore, the efficiency of that relationship is better over a dataset that comes from industry because of the quality of data collection. Our comment on the findings is that it is better to exclude environmental factors from calculating UCP and make them available only for computing productivity. The study also encourages project managers to understand how to better assess the environmental factors, as they do have a significant impact on productivity. KEYWORDS environmental factors, software effort estimation, software productivity, use case points 1 | INTRODUCTION Software effort estimation is necessarily required at the inception phase to bid for a software project and assign human resources. 1-45 Since very little data are known at this stage, managers turn their attention to software size metrics, which can help in providing a general sense about the most likely effort of a software project. Functional size metrics, such as function points (FP) 5 and use case points (UCP), 6 are well suited measures for such a problem. The FP has long been studied and examined as a more efficient size measure. 7,8 Nevertheless, measuring FP is tedious and requires intensive care, especially counting FP components such as internal, external, and query functions, in addition to evaluating environmental and complexity factors. 3,9 More recently, the UCP method has attracted more attention from researchers as a competitive sizing method to FP at the early phases of software development. The UCP was first introduced by Karner 6 in 1993 to estimate the size of object-oriented software projects. The basic idea of constructing UCP was inspired by the FP method. The typical input of UCP is the UML use case diagram, which describes the functional requirements in UML annotations such as actors, use cases, and various kinds of relations. 10 The UCP is computed by converting the elements of use case diagrams into their corresponding size metrics through a well-defined procedure. The accuracy of the UCP ...

Categorical Variable Segmentation Model for Software Development Effort Estimation

“…The IFPUG method provides complexity measurements, (size), only. If a software development effort -(time in person-hours), is needed; a productivity factor (PF) has to be used to obtain the number of personhours [10]. The proposed CVS model can be used for the estimation of the software development effort in person-hours.…”

“…The original IFPUG method leads to complexity measurements, (size). If a software development effort -(time in person-hours) is needed, then a Productivity Factor (PF), has to be used for the transformation of the estimated size into the number of person-hours [10].…”

A model of owner estimate cost for software development project in Indonesia

“…The results showed that the use of the subset selection method could improve the level of predictive accuracy. 12 The study that examines other UCP elements, namely, productivity projects was carried out by Azzeh and Nassif 13 who examined the relationship between productivity of project and environment factors (EFs) in UCP in which project productivity is a key factor to obtain estimation effort.…”

“…Other researchers called ER with the term productivity factor (PF) 10 or project productivity, 13,15 others call it person-hours. 30 The ER value is set equal to 20 man-hours/UCP.…”

Project productivity evaluation in early software effort estimation

“…Then the productivity and UCP are used within a log‐linear regression model to calculate the software effort. Azzeh et al studied and investigated the relationship between environmental factors and productivity. They found that the environmental factors can work as good indicator for productivity prediction when historical data are available.…”