Optimisation analysis for reliability assessment based on stochastic differential equation modelling for open source software

A new distributed software development paradigm typified by such open source project will evolve at a rapid pace in the future. Especially, open source software (OSS) which serve as key components of critical infrastructures in the social life are still ever-expanding now. We propose a software reliability growth model based on stochastic differential equations in order to consider the active state of the open source project. Especially, we assume that the software failure intensity depends on the time, and the software fault-reporting phenomena on the bug-tracking system keeps an irregular state. Moreover, it has been necessary to manage the software development process in terms of reliability, development effort and version-upgrade time. We find the optimal version-upgrade time based on the total expected software maintenance effort. We show that the proposed model can assist improvement of quality for OSS systems developed under the open source project.