Simulating the Software Development Lifecycle: The Waterfall Model

(1) Background: This study employs a simulation-based approach, adapting the waterfall model, to provides estimates for projects and individual phase completion times. Additionally, it pin-points potential efficiency issues stemming from a suboptimal resource level. It further demonstrates how one can go on to identify a resource level that effectively eliminates bottlenecks and curtails the idle time of resources. (2) Methods: We implement our software development lifecycle using SimPy, a discrete-event simulation framework written in Python. Our model is executed on 100 projects of varying sizes over three stages. The first, pre-optimization, provides insight based on the initial set of resources. This is followed by the optimization stage, which serves to identify the optimal number of resources to eliminate bottlenecks and minimize idle time. The third stage, post-optimization, evaluates the resource optimized model. (3) Results: The analysis of the simulation-generated data reveals the presence of resource bottlenecks during the pre-optimization stage, particularly in the implementation phase. These dissipate after optimization. (4) Conclusions: The findings emphasize the advantage of using simulation as a safe and effective way to experiment and plan for software development projects. Such simulations also allow those man-aging software development projects to make accurate, evidence-based projections as to phase and project completion times and identify optimal resource levels and their interplay. In particular, understanding the tradeoffs between experiencing delayed completion times and procuring additional resources to alleviate any bottlenecks.