The discrete time/resource trade-off problem in project networks: A branch-and-bound approach

In many solution methods for resource-constrained project scheduling, it is assumed that both the duration of each activity and its resource requirements are known and fixed. In real-life projects, however, it often occurs that only one renewable bottle-neck resource is available and that the activities have a total work content which indicates how much work (expressed in man-periods) has to be performed. The objective then is to schedule each activity in one of its possible execution modes, subject to the precedence and resource constraints, in order to minimize the project makespan. We present a branch-and-bound procedure and report computational results, obtained using a full factorial experiment on a randomly generated problem set.