The optimal concurrent strategy for product design

Decompose the concurrent completion time of two sequential tasks into basic design time and repetition time of downstream task. The repetition time of downstream task is influenced by the uncertainty of upstream design information and dependency of downstream task upon upstream uncertainty. The uncertainty is defined as the average frequency of engineering change of upstream task which decreases with information modification. An influence function is introduced to define the dependency of downstream task upon upstream uncertainty. An analytical model of the concurrent completion time is developed to find the optimal concurrent strategy for two sequential tasks. The influences of parameters on concurrent strategy are also discussed.