Software process simulation for reliability management

Abstract

This paper describes the use of a process simulator to support software project planning and management. The modeling approach here focuses on software reliability, but is just as applicable to other software quality factors, as well as to cost and schedule factors. The process simulator was developed as a part of a decision support system for assisting project managers in planning or tailoring the software development process, in a quality driven manner. The original simulator was developed using the system dynamics approach. As the model evolved by applying it to a real software development project, a need arose to incorporate the concepts of discrete event modeling. The system dynamics model and discrete event models each have unique characteristics that make them more applicable in specific situations. The continuous model can be used for project planning and for predicting the effect of management and reliability engineering decisions. It can also be used as a training tool for project managers. The discrete event implementation is more detailed and therefore more applicable to project tracking and control. In this paper the structure of the system dynamics model is presented. The use of the discrete event model to construct a software reliability prediction model for an army project, the Crusader, is described in detail.