Release and testing stop time of a software: A new insight

Testing is a vital phase in the software development life cycle. But, the way it is performed, varies from one organization to another. One of the prime concern in software industry is to determine the optimal duration of testing. Both researchers as well as software developers have been working towards solving this issue since long. The duration of testing is directly proportional to its reliability level but prolonged testing costs a lot in terms of higher testing and market opportunity cost. Therefore determination of optimal testing time has become an important optimization problem in the field of software development. As a common industrial practice, software release also marks the end of testing phase of a software. But, this often accompanies issues like delayed release in case the testing is continued to ensure a high reliability level or a low reliability level in case the software is released early. To counter these problems, now a days testing is divided into two phases i.e. pre-release and post release testing phase. During post release testing phase organization aims at treating remaining software faults and subsequently enhance product experience for customers. In this paper we present a generalized approach of optimal scheduling policy to determine the optimal release and testing stop time of a software while minimizing overall testing cost. In our proposed work, software testing & operational phases are governed by different distribution functions in distinct phases, i.e. in prerelease, post release phase (before and after testing stop time) in our proposed cost model. Numerical example is given to support our findings with the help of a real life software failure data set of Tandem Computers.