Integrated Inbound and Inplant Logistics for the Movement of Containers Via Heterogeneous Material-Handling Resources for Better Operational Efficiency

This paper addresses the integrated inbound and in-plant logistics for moving part containers from docks to their respective storage areas, usually termed as marketplaces, within a manufacturing plant. Heterogeneous Material Handling Resources (MHRs) are utilized for this movement. A mixed integer linear programming (MILP) model is proposed to minimize the makespan with respect to the transport of a container to its marketplace. The present study is inspired by a real-life case of a manufacturing plant, and it is possibly the first of its kind that explores the integration of inbound and in-plant logistics and tackles the operational issues of the assignment and sequencing of incoming trucks at the dock as well as the scheduling-sequencing of all containers via MHRs. The model, thus, ensures complete information on container movement from the dock to their respective marketplaces. It aims to tackle operational problems like dock congestion, schedule changes, inventory management, part rejections, part unloading delays, MHR availability, and maintenance and ensure uninterrupted part deliveries. Further, we propose a Divide-Fix, Fix-Optimize and Overarching Generate-Optimize technique that uses heuristics and three modified metaheuristics: Population-based Multi start Simulated Annealing, Hybrid Harris Hawks Optimization, and Opposition-based Whale Optimization Algorithm to solve larger instances. As the strategy uses the MILP model as part of the solution approach, the results obtained are either optimal or within the optimality gap of 3%. The latter two metaheuristics are possibly applied first time in such a problem setting and found to achieve stable results with low confidence interval