System engineering encapsulation of reliability techniques

Development of an end-to-end software system requires comprehensive reliability-driven treatment. Therefore, all phases of the system engineering life-cycle require adequate treatment from the reliability perspective. Research in software engineering also indicates that early removal of faults is critical to the success of a reliable software system. A combined treatment of reliability engineering and software life-cycle can provide the capability of reliability estimation to designers to help them clarify, analyze and verify the reliability requirement in the early phases of the life-cycle. The broad goal of our research is to provide a computer aided reliability engineering (CARE) tool that can be used across the software development life-cycle. We present a reliability based software development process and an end-to-end reliability estimation of a multi-module software system. The end-to-end reliability estimation analyzes the reliability parameters of each module (or components) as well as the data and control flows among them to provide accurate reliability parameters of the software system. The reliability information can be used in high level design phases as well as in testing. We propose a multi-module based reliability estimation approach that, by using a resolution function, can model the fault propagation amongst the modules and links. This approach includes both data and control flow structure of the program, as well as provisions for looping structure in the program. Implementation issues of this approach to the CARE tool is discussed.