A time-oriented branch-and-bound algorithm for resource-constrained project scheduling with generalised precedence constraints

Resource-constrained project scheduling with generalised precedence constraints is a very general scheduling model with applications in areas such as make-to-order production planning. We describe a time-oriented branch-and-bound algorithm that uses constraint-propagation techniques which actively exploit the temporal and resource constraints of the problem in order to reduce the search space. Extensive computational experiments with systematically generated test problems show that the algorithm solves more problems to optimality than other exact solution procedures which have recently been proposed, and that the truncated version of the algorithm is also a very good heuristic.