Early stage software reliability and design assessment

In early developmental stages of software, failure data is not available to determine the reliability of software, but design assessment is a must in this stage. We propose a model based on reliability block diagram (RBD) for representing real-world problems and an algorithm for analysis of these models in early phase of software development. We have named this technique early reliability analysis technique (ERAT). We have performed several simulations on randomly generated software models to compute reliabilities and coupling parameters. The simulation result shows that reliabilities are good quality indicator and coupling can be correlated with system reliability and can be used for system design assessment.