The resource restrict in product development processes greatly influences on the cost and progress of the whole project. In this paper, a task priority algorithm that can solve the problem of resource competition, taking the related theory of project management into consideration comprehensively, is proposed. A ﬂexible model of product development process is described based on hierarchical colored Petri net. And then a resource coordination mechanism is modeled according to the characteristic of modern product development processes. Finally, a resource allocation process is analyzed and optimized in order to enhance the utilization efficiency of resource and to shorten the product development time.