A Design Process Modeling Approach Incorporating Nonlinear Elements

This paper extends the literature of engineering design process modeling. We focus on the modeling of design iterations using a task-based description of a development project. We present a method to compute process performance and to relate this outcome to critical activities within the process. Design tasks are modeled as discrete-event activities with design information flowing between them. With every design task, we associate process characteristics such as the completion time and cost per time unit for the task. These characteristics can change with the advance of the design process. The method is especially suited for comparison of different design processes on the basis of overall process costs and lead time. In order to illustrate the method a simple design process was modeled as an example. Based on this model the process lead time distribution and the process costs were simulated.