The resource transfer Problem: Modeling and solving integrated scheduling and routing problems

The resource transfer problem (RTP) is a generic framework for integrated scheduling and routing problems, which allows for modeling and solving complex scheduling and rich vehicle routing problems as well as their hybrids in a unified way. Many constraints and specific requirements arising in scheduling and routing applications are covered by the RTP. Basically, the problem consists in scheduling a set of activities that have to be performed at different locations in a network. The activities can be executed in alternative modes, using different amounts of resources. The resources can be transferred between the locations and may require sequence-dependent changeovers between consecutive activities. Moreover, generalized precedence relations between the activities have to be taken into account. For solving the RTP we propose a time-oriented branch-and-bound algorithm exploiting constraint-propagation techniques to reduce the search spaces. We report on computational experience on a set of integrated supply chain scheduling and routing problems.