Constraint-based schedule repair for product development projects with time-limited constraints

In today's changing marketplace, accurate project planning and scheduling for product development becomes difficult. It is important for an R&D organization to quickly recognize the impact of unexpected events and rapidly reschedule product development projects. In addition, it has become more important for a firm to meet the due date requirement for a product development project than to satisfy the available resource capacity, since a late project will incur a great sales loss or a large amount of penalty to customers. This paper models the scheduling of product development projects as a dynamic constraint satisfaction problem, where the due date constraint is considered as a “hard” constraint that cannot be violated. All unexpected changes during the product development are regarded as additions or deletions of constraints to the problem. A reactive scheduling methodology based on the meta-heuristic approaches is developed to repair a disrupted schedule with the minimum cost of resource conflicts. The proposed approaches have been tested on several benchmark problems and satisfactory results have been obtained.