Automatic simulation to predict software architecture reliability

One of the goals of software architecture research is to analyze the reliability of a software system early in the development lifecycle. This allows the system designers to predict reliability and evaluate alternative designs. This paper presents a methodology and accompanying toolset, Workflow-to-SDL-Direct-Simulation (W2S), for generating a simulator from a semi-formal architecture description. This simulator allows the analysis of the system's reliability based on the simulated behavior and performance. There are three steps in the W2S methodology: translation of the description to a communicating extended finite state machine (CEFSM) model; generation of a simulator from the CEFSM model and a model of the system environment; and execution of the simulator on top of an underlying CEFSM engine. The W2S methodology was applied to a Bellcore telecommunication control system, using a set of tools that we developed. Several sets of experiments were carried out. The result shows that the information generated by the simulator can be used to predict the reliability of a system solely based on its architectural description. This prediction allows designers to select more reliable architectures.