A Study of Using Two-Parameter Generalized Pareto Model to Analyze the Fault Distribution of Open Source Software

In the modern society, software plays a very important part in many security-critical or mission-critical systems. Consequently, the main goal of project managers and software engineers is to develop and deliver reliable software within very limited resource, time, and budget. In the past, some research reports showed that the Weibull distribution (WD) and the Pareto distribution (PD) models can be used to describe the distribution of software faults. In this paper, based on our previous study, we further propose and show how the two-parameter generalized Pareto distribution (2-GPD) can be used to model the distribution of software faults. Some mathematical properties of proposed model are analyzed and presented. Experiments based on open source software (OSS) are performed and discussed in detail. Evaluation results show that the proposed 2-GPD model eliminates some issues in modeling that arise in the PD model and has a fairly accurate prediction capability of fault distributions of OSS and depicts the real-life situation more faithfully.