Optimal COTS selection for fault tolerant software system with mandatory redundancy in critical modules using consensus recovery block scheme under fuzzy environment

The dependence of mankind on software systems has made it necessary to produce highly reliable software. Software reliability is the major dynamic attribute of the software quality. Hence, it is essential to ensure software reliability for software products. The computer revolution has benefited society and increased the global productivity, but a major threat of this revolution is that the world has become critically dependent on the computing systems for proper functioning and timing of all its activities. While designing software it becomes very important to identify the critical modules in a software system. A system can be made fault tolerant by adding redundant components. Adding redundancy in critical modules may increase the reliability of the system and hence prevents system failure. So this paper aims at optimal selection of COTS components by minimizing the absolute deviational execution time by simultaneously maximizing the system reliability with a constraint on criticality of modules under fuzzy environment.