A Software Development Simulation Model of a Spiral Process

This paper will present a discrete event simulation model of a spiral developmentlifecycle that can be used to analyze cost and schedule effects of using sucha process in comparison to a waterfall process. There is a need for simulationmodels of software development processes other than the waterfall due to newprocesses becoming more widely used in order to overcome the limitations ofthe traditional waterfall lifecycle. The use of a spiral process can make theinherently difficult job of cost and schedule estimation even more challengingdue to its evolutionary nature, but this allows for a more flexible process that canbetter meet customers’ needs. Cost figures for the spiral process may initiallyappear higher but can ultimately prove to be much more realistic or even lowerthan the final cost for a waterfall process since the data on which they are basedis continuously updated. The goal of this work is to present a preliminary modelthat provides insight into the impacts of selecting a spiral development approachand that demonstrates the usefulness of such a model in order to encourage thedevelopment of more detailed spiral development models.