Time/Cost optimization: A research overview

The discrete time/cost trade-off problem is a well-known project scheduling problem in literature that assumes the duration of project activities to be discrete, non-increasing functions of the amount of a single non-renewable resource. The problem has been studied under three possible objectives. The so-called deadline problem involves the scheduling of project activities in order to minimize the total cost of the project while meeting a given deadline. The budget problem aims at minimizing the project duration without exceeding a given budget. A third objective involves the generation of the complete efficient time/cost profile over the set of feasible project durations.

In the past +10 years, the OR&S group has investigated this challenging problem from various angles, and has developed an exact branch-and-bound procedure as well as different meta-heuristics. Moreover, extensions to the presence of time/switch constraints and three types of payment models have been investigated in the last few years. The Project Scheduling Game (PSG) has been used in various countries to learn managers how to balance between time and costs of projects, and the game has been a foundation for various research papers.

The time/cost research page can be found at the OR&S website here.