Collection and sorting debris management after technological disasters

This study is dedicated to the first relief phase after technological disasters, which consists of collecting and sorting materials. This phase precedes the introduction into the circular economy. The main motivation is to re-use or recycle materials, which reduces the extraction of raw materials from the environment. For such a purpose, the disaster site is divided into areas and the extraction considers horizontal and vertical constraints. This is due to the unstable state of the debris structure. Three objectives are addressed, the quality of materials, the total cost, and the total time. The problem is referred to as the Multi-objective Multi-mode Resource Constrained Project Scheduling Problem in Disaster Relief (2M-RCPSP-DR). We propose a multi-objective mathematical formulation, exact methods based on the ϵ-constraint, and a multi-objective NSGAII based metaheuristics. Other than a classical NSGAII, four variants are developed, where a local search is integrated into the NSGAII using different strategies. Experiments and analyses are conducted to validate and evaluate the performance of the proposed models and methods.