DISCRETE TIME/COST TRADE-OFF PROJECT SCHEDULING PROBLEM - AN APPLICATION TO THE MINISTRY OF HEALTH PROJECTS

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2022-4
Akbudak, Özlem
The Discrete Time/Cost Trade-off (DTCT) problem is a widely studied and important research area in project scheduling literature. Decision-makers try to select the best schedule alternative when there are two or more conflicting criteria. So-called Time/Cost Trade-off problems represent the two conflicting criteria generalized as time and cost. Decreasing the processing time of a task requires more resources which demand additional cost. This study focuses on the DTCT problems where some of the tasks have due dates. If a completion time of a task exceeds the due date of a task, we face tardiness. We aim to find the best solution in terms of cost, with the total tardiness not exceeding the maximum allowable total tardiness level. We take our motivation from the two Information Technology projects that were most recently undertaken in the Ministry of Health. We construct a mixed integer linear programming model for this well-defined problem. Additionally, we propose a heuristic approach, which makes use of the optimal solutions of the Linear Programming Relaxation of the model. We tested the performance of the mathematical model and heuristic approach on several instances taken from the literature and on the two Ministry of Health projects, and report favorable results. Besides, one of the well-known Evolutionary Algorithm is applied to generate all non-dominated objective vectors with respect to the total cost and total tardiness criteria. We illustrate the algorithm on the two Ministry of Health projects.

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Citation Formats
Ö. Akbudak, “DISCRETE TIME/COST TRADE-OFF PROJECT SCHEDULING PROBLEM - AN APPLICATION TO THE MINISTRY OF HEALTH PROJECTS,” M.S. - Master of Science, Middle East Technical University, 2022.