Scheduling of multiple projects with resource transfers

Abstract

In organisations, dealing with projects, multiple projects are run simultaneously sharing a common pool of resources. The resources in such a multi-project environment are generally transferred between the projects, consuming significant amounts of both time and cost. In most of the existing models for multi-project planning and scheduling, however, these transfers are implicitly assumed to occur instantaneously with no extra cost. This assumption of instantaneous resource transfers, in most of the practical situations, is not valid and thus may lead to unrealistic schedules. This article is aimed at modelling of these transfers of resources in multi-project scheduling. A generalised model for inter-project resource transfers is presented and an integer linear program is proposed for minimising the penalty/reward for tardy/early projects, and the cost of idleness and transfer of the resources. A heuristic procedure is also developed and computational results are reported.