Dynamically Weighted Combination Model for Describing Inconsistent Failure Data of Software Projects

Abstract

Background/Objective: The Software Reliability Engineering discipline is witnessing continued research in the field of Software Reliability Growth Models (SRGMs), in order to develop suitable models so as to match with the phenomenal developments in the software sector. The objective of this paper is to propose a combined dynamically weighed model for reliability analysis. Methods: In general, the ability of a model to describe a dataset adequately is assessed by Goodness of Fit (GoF) measures that a model achieves. We used one of the difficult data sets for evaluation of the GoF performance and the non-linear regression was carried out using Curve fitting application of the MATLABTM software tool. The coefficients of determination R-Square (R2), Sum of Squared Error (SSE), Root Mean Square Error (RMSE) are the different GoF metrics used. Findings: The major challenge for the software projects today, is to measure, analyze and control the level of quality of the delivered software. Undesirably long testing cycles adversely influence time to market and hence software development organizations are very keen on having a good control on the testing cycle. In the last few years many reliability models have been identified and recommended. However, no single model can be considered suitable for all situations. Some models assume the growth of mean value function to be exponential, while other models assume it to follow S-type growth. This poses a challenge to the reliability modeling. The dynamically weighted combination model that we propose in this paper helps to address both the phenomena. The superposition and time transformation property of Non-Homogenous Poisson Process (NHPP) model was considered to derive the proposed model. Application: Using SRGM helps to improve the reliability performance. We have derived a powerful model by combining two well-known models. The proposed model gives excellent GoF performance and provides more confidence both for the customer and for the software development organizations.