Scheduling Repetitive Construction Projects Using Fuzzy Linear Programming

Scheduling problem for repetitive construction projects involves three conflicting objectives. These objectives are project duration, project total cost, and project total interruption time. This paper presents a multi-objective fuzzy linear programming model (FLP) for resolving this problem. Literature concerned with scheduling problems for repetitive construction projects was reviewed. Multi-objective fuzzy linear programming was then explained. The proposed model formulation was then presented. A bridge project from pertinent literature was selected for model validation purpose. An optimization of each individual objective was performed with a linear programming (LP) software (Lindo) that gave the upper and lower bounds for the multi-objective analysis. Fuzzy linear programming was then applied to optimize the solution. Two scenarios were adopted in solution. In the first scenario, the three above objectives were considered simultaneously. Analysis of the results revealed that project duration, and project total cost are deviated only by 7.2%, and 1.8%, respectively as compared to their corresponding ideal values in the crisp LP model. On the other hand, the percentage of total interruption time to project duration in FLP is 5.3% against zero in LP. In the second scenario, each two objectives were considered in a single run. The purpose is to explain how can the model's user generate and evaluate the optimal tradeoff solution between any two objectives that suit his demands.