Abstract: Due to the high dependency on software, the measurement of its performance has become vital. It is a common practice in the software industry to test products exhaustively before release so that the maximum number of faults is detected and removed. Fault detection and the removal rate are governed by many factors such as changes in testing environment, testing strategies, skills, efficiency, etc. The point at which a change in the fault detection rate occurs is known as the change point. Due to the increasing demand of good quality software in a short span and to remain in the market competition, firms are providing warranties on their products to assure reliability. The defects reported during the operational phase are fixed by providing patches. However, delivering patches after release demands extra effort and resources, which is costly and hence not economical for the firms. Considering the above factors, an effort-based cost model with change point and warranty is proposed in this work to determine the optimum release and patch time of a software by minimizing the overall cost. A numerical illustration is provided to validate the proposed cost model.

Key words: software reliability, test effort, cost, modeling release, testing, patch, change point, warranty