A Nonparametric Approach to Software Reliability

In this paper we present a new, nonparametric approach to software reliability. It is based on a multivariate counting process with additive intensity, incorporating covariates and including several projects in one model. Furthermore, we present ways to obtain failure data from the development of open source software. We analyze a dataset from this source and consider several choices of covariates. We are able to observe a different impact of recently added and older source code onto the failure intensity. KEY WORDS: software reliability, open source software, multivariate counting processes, Aalen model, additive risk model, survival analysi