An optimization-based approach for distributed project scheduling

Pressed by market globalization, a recent trend for manufacturers is to have their design teams at different locations to better serve local markets and reduce design costs. Under the concurrent engineering paradigm, tasks in a design project are required to be performed in parallel, however, are often interdependent in a complex way. As a result, effective communication and coordination among teams become vital for a project to be successful. The complex interdependencies have not been adequately addressed in the literature. This paper presents a novel optimization formulation that explicitly models the interdependencies among tasks and the communication activities required. A solution methodology that combines Lagrangian relaxation and the surrogate subgradient method has been developed to solve the optimization problem that is inseparable. Backward/forward Dynamic programming is used to solve task subproblems. Numerical results demonstrate that complex dependencies among tasks are satisfied via communication activities, and near-optimal schedules are efficiently obtained.