Scheduling Projects with Converging and Diverging Material Flows Using IBM ILOG CP Optimizer—An Experimental Performance Analysis

We study the problem of scheduling construction or deconstruction projects subject to temporal and renewable resource constraints to minimize the makespan. Moreover, we take into account material flows between activities of the project. Material flows can cause delays due to the limited capacity of intermediate storage facilities. In construction projects, material flows follow a convergent structure as materials are supplied, pre-treated, and mounted throughout the project. In deconstruction projects, materials are released, treated and removed from the site, resulting in a divergent structure. An experimental performance analysis with IBM ILOG CP Optimizer on generated test instances reveals that solving the problem with converging material flows requires a multiple of the computation time for solving the problem with diverging material flows.