Reliability Evaluation of Software Architecture Styles

In process of software architecture design, different decisions with system-wide impacts are made. An important decision of design stage is the selection of appropriate software architecture style. Since quantitative impacts of styles on quality attributes have not been studied yet, their application is not systematic. Since Reliability is one of the essential quality requirements of software systems, especially for life critical ones, one of the main criteria in choosing architecture style of these systems is high reliability. The goal of this study is to quantify the impact of architecture styles on software reliability that is desired quality of life critical software. We evaluate styles through reliability block diagram method. First, the reliability equation of each architectural style was computed using of Reliability block diagram approach. Then, reliability rank of architectural styles is computed by setting of the number of effective components in a transaction parameter in reliability equation of architectural styles. The main innovation of this article is quantification of impact of styles on software reliability that is essential for style selection.