A model of the software development process using both continuous and discrete models

Software process models have been simulated using system dynamics and discrete modeling paradigms. System dynamics models describe the interaction between project factors, but do not easily represent queues and discrete process steps. On the other hand, discrete event models describe process steps, but may not have enough events to represent feedback loops accurately. We develop a combined model that represents the software development process as a series of discrete process steps executed in a continuously varying project environment. We demonstrate the feasibility of this model by combining a discrete event model of the ISPW6 software process example with the system dynamics model developed by Abdel-Hamid and Madnick [Abdel-Hamid and Madnick 91]. The combination of these two modeling paradigms creates the opportunity to examine new problems and issues that are highly relevant to software project managers.