A software cost model with warranty and risk costs

In this paper, a cost model with warranty cost, time to remove each error detected in the software system, and risk cost due to software failure is developed. A software reliability model based on non-homogeneous Poisson process is used. The optimal release policies to minimize the expected total software cost are discussed. A software tool is also developed using Excel and Visual Basic to facilitate the task of determining the optimal software release time. Numerical examples are provided to illustrate the results.