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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. 


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.

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.


The DTCTP has been extended to a project owner/contractor setting in which incentives are optimised. 

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.