Net Present Value in Scheduling

Optimizing cash flows in project management

The research on optimizing cash flows of project activities in order to maximize the net present value has gained a renewed attention since Pieter Leyman has been awarded by the PMI Belgium Thesis Award in 2012. During his work on this topic, he has build further on the recursive npv method developed at the OR&S group (see the npv page of the group) and has written a new paper entitled "A new scheduling technique for the resource-constrained project scheduling problem with discounted cash flows" that has now been published in the International Journal of Production Research

Abstract: In this paper we discuss the resource-constrained project scheduling problem with discounted cash flows (RCPSPDC). We introduce a new schedule construction technique which moves sets of activities to improve the project net present value (NPV) and consists of two steps. In particular the inclusion of individual activities into sets, which are then moved together, is crucial in both steps. The first step groups activities based on the predecessors and successors in the project network, and adds these activities to a set based on their finish time and cash flow. The second step on the contrary does so based on the neighbouring activities in the schedule, which may but need not include precedence related activities. The proposed scheduling method is implemented in a genetic algorithm (GA) metaheuristic and we employ a penalty function to improve the algorithm's feasibility with respect to a tight deadline. All steps of the proposed solution methodology are tested in detail and an extensive computational experiment shows that our results are competitive with existing work.