Testing-Effort Dependent Software Reliability Model for Distributed Systems

Distributed systems are being developed in the context of the client-server architecture. Client-server architectures dominate the landscape of computer-based systems. Client-server systems are developed using the classical software engineering activities. Developing distributed systems is an activity that consumes time and resources. Even if the degree of automation of software development activities increased, resources are an important limitation. Reusability is widely believed to be a key direction to improving software development productivity and quality. Software metrics are needed to identify the place where resources are needed; they are an extremely important source of information for decision making. In this paper, an attempt has been made to describe the relationship between the calendar time, the fault removal process and the testing-effort consumption in a distributed development environment. Software fault removal phenomena and testing-effort expenditures are described by a non-homogenous Poisson process (NHPP) and testing-effort curves respectively. Actual software reliability data cited in literature have been used to demonstrate the proposed model. The results are fairly encouraging.