Iterative Approach based on Constraint Programming for the RCPSP with Transportation
Résumé
Integrated problem with transportation and scheduling problems encompasses many constraints including for example the precedence and synchronization constraints between transportation operations and scheduling operations. Exact resolution based on linear formulation or heuristic based approaches expect difficulties in finding a simple feasible solution due to the large number of binary variables and big M required by the model.
The transportation problem in the RCPSP consists in the transportation of resources required by activities using a fleet of homogenous vehicle of limited capacity. Computation of a flow permits to have the pickup activity, the delivery activity with the quantity and the transportation problem is then a PDP problem that must be solved. The optimal RCPSP flow does not lead to an optimal solution of the RCPSP with transportation and an iterative search procedure is required. We introduced a decomposition-based approach with a constraint programming modeling and the experiments have been achieved with Choco Solver.
Our research is now directed on the RCPSP with transportation considering n-to-n PDP that required computation of transportation solution where the vehicles can achieve trip with several consecutive pickup operations.