Time/cost trade-offs
Time/cost trade-off problem in project scheduling
Exact procedures
The paper of Demeulemeester et al (1998) discusses new results for the DTCTP in project scheduling using a new branch-and-bound procedure. The procedure makes use of an extended version of the well-known Fulkerson algorithm to calculate lower bounds with convex piecewise linear estimations. The procedure is tested on the so-called BMF set which can be downloaded in the link below.
- Demeulemeester, E., De Reyck, B., Foubert, B., Herroelen, W. and Vanhoucke, M., 1998, “New computational results on the discrete time/cost trade-off problem in project networks”, Journal of the Operational Research Society, 49, 1153-1163.
- Download the project data of this paper here.
Heuristics
Three extensions to the DTCTP are discussed in the paper of Vanhoucke & Debels (2007). A heuristic solution procedure is proposed for the time-switch, work continuity and net present value extensions.
- Vanhoucke, M. and Debels, D., 2007, “The discrete time/cost trade-off problem: extensions and heuristic procedures”, Journal of Scheduling, 10, 311-326.
- Vanhoucke, M., 2015, "Generalized discrete time-cost tradeoff problems", in C. Schwindt & J. Zimmermann, eds. Handbook on Project Management and Scheduling Vol.1. Springer, pp. 639–658.
Time/switch constraints
The DTCTP with time-switch constraints, which force periods of inactivity in the project activities, is handled by Vanhoucke et al (2002). The paper of Vanhoucke (2005) builds on the previous research and proposes new computational results for the DTCTP with time-switch constraints.
- Vanhoucke, M., Demeulemeester, E. and Herroelen, W., 2002, “Discrete time/cost trade-offs in project scheduling with time-switch constraints”, Journal of the Operational Research Society, 53, 741-751.
- Vanhoucke, M., 2005, “New computational results for the discrete time/cost trade-off problem with time-switch constraints”, European Journal of Operational Research, 165, 359-374.
Incentives
The DTCTP has been extended to a project owner/contractor setting in which incentives are optimised.
- Aouam, T., and Vanhoucke, M., 2019, "An agency perspective for the multi-mode project scheduling with time/cost trade-offs. Computers and Operations Research", 105, 167–186.
Business Game
The well-known Project Scheduling Game is a game to optimize time/cost trade-offs in a dynamic setting. It is used at universities and business schools, and has been the foundation for several research papers.
- Vanhoucke, M., Vereecke, A. and Gemmel, P., 2005, "The project scheduling game (PSG): simulating time/cost trade-offs in projects", Project Management Journal, 36(1), 51–59.
- Vanhoucke, M. and Demeulemeester, E., 2003, "The application of project scheduling techniques in a real-life environment", Project Management Journal, 34, 30–42.
Payment models
The net present value variant of the DTCTP is applied to three payment models in the work of Leyman et al (2019). Different metaheuristics and solution representations are applied to the three models.
- Leyman, P., Van Driessche, N., Vanhoucke, M. and De Causmaecker, P., 2019, "The impact of solution representations on heuristic net present value optimization in discrete time/cost trade-off project scheduling with multiple cash flow and payment models", Computers and Operations Research, 103, 184–197.
- Download the created value data of this paper here.