SQMMA: Software Quality Model for Maintainability Analysis

Abstract

Software Quality is generally characterized by several factors which reveal the degree of success of the software developed and its future maintainability. Although many existing models provide frameworks of huge potential pertaining to quality analysis, yet offer little support to make them operational and handy to use. Nonetheless, by taking ideas from existing models, new metrics, their relationships with external quality factors and associated weights can be defined and evaluated. Keeping these views in mind, this paper proposes a new quality model (SQMMA) which offers ready-to-use mathematical formulas to quantify four quality attributes namely Analyzability, Changeability, Stability and Testability as weighted sum of a set of software code metrics. These attributes further act as determinants to evaluate `Maintainability' characteristic of a software, according to ISO 9126 definition. A revised formula to compute Maintainability, according to ISO 25010, has also been derived. The designed model is then implemented on four versions of Apache tomcat and results are presented. Finally results have been validated through their trend analysis and comparison with bugs/change metrics drawn additionally.