When to stop testing multi upgradations of software based on cost criteria

Software testing is an important phase of the software development life cycle to achieve highly reliable software. Due to the time and resource limitation during the testing phase, firms do not attempt to deliver a complete and perfect product in one development cycle. They plan multi upgradations of software by adding new functionalities. Many models have been developed in the past which discuss about when to stop testing and when to release the software to the users. But they have been limited to the study of single version only. In the present framework, we describe a unified approach to address an important issue of when to stop testing the multi-upgradation of software, which is a complex process. The total debugging cost for each upgradation includes the cost of debugging in the warranty period along with the testing cost. It is assumed that the software is supported till the warranty period is over. In the proposed cost model for each upgradation, we consider that some of the remaining faults of previous release are reported and removed partly during the testing period and partly during the warranty period of new upgradation. An algorithm for finding the optimal release time for each version is developed. We estimate the parameters of the model using Statistical Package for Social Sciences on the real data set, and obtain optimum stopping time for each version of the software using Maple software.