A Quantitative Approach to the Process Modeling and Planning in Concurrent Engineering

This paper deals with the quantitative modeling and planning of the product development process in concurrent engineering (CE). CE requires that product design and its related process design be carried out concurrently. Many existing CE models highlight the impact of the upstream design on the downstream design. While in our research, a quantitative model of the product development process in CE based on the network of product–process design activity pairs is presented to describe both the impact of the upstream product design on the downstream process design and the process design’s ability of discovering the faults in the product design. Based on this model, a method is presented to determine the appropriate concurrency degree between the product and process design activities and estimate the mean duration of product–process design activity pair. Then an approach is proposed to solve the integrated optimization problem of both the allocation of resources and the planning of the product development process in CE. Its objective is to allocate the resources for the product development project reasonably to complete it before the due date, minimize its lead-time and keep the average resource utilization rate above a given level. Unlike other project scheduling problems with pre-determined numbers of the resources allocated for the project, in our research, the numbers of the resources allocated for the project are determined along with the project planning. To solve the problem, a branch-and-bound algorithm is proposed and a heuristic rule is introduced to improve its efficiency. The computational result of an example from an automobile factory shows the effectiveness of the algorithm.