A flexible stochastic differential equation model in distributed development environment

In recent years, the dependence on a computer system has become large in our social life. Especially, a software development environment has been changing into distributed development environment interconnected with work-stations. Therefore, it becomes more difficult for software developers to produce highly reliable software systems efficiently, because of the more diversified and complicated software requirements. Also, in the software development process, the software testing-cost occupies more than a half of the total development cost. In this paper, we derive a flexible stochastic differential equation model describing a fault-detection process during the system testing phase of the distributed development environment by applying a mathematical technique of stochastic differential equations of an Itô type. Moreover, we discuss optimal software release problems based on the reusable rate of software components minimizing the expected total software cost, and also minimizing the cost with satisfying a software reliability requirement based on the coefficient of variation.