A Material-Aware Scheduling Framework with Cooperative Search for Flexible Job Shop Scheduling with Material Kitting Constraints

Abstract

Flexible job shop scheduling has been widely investigated in manufacturing systems. However, most existing studies implicitly assume that all required materials are available when operations become ready for processing. In practical production environments, materials are often delivered in dispersed batches, which may interrupt operation execution and lead to infeasible schedules. In this paper, flexible job shop scheduling with material kitting constraints is investigated, where operation feasibility is jointly determined by machine availability, technological precedence, and material availability over time. A material-aware scheduling framework is developed, in which a decoding mechanism explicitly incorporates material arrival information and dynamically adjusts operation start times. An insertion mechanism is further introduced to utilize material waiting windows and reduce idle machine time. To enhance solution quality under strict feasibility requirements, a cooperative search strategy is employed, in which feasibilityoriented scheduling is supported by auxiliary exploration under relaxed material constraints. Numerical experiments demonstrate that the proposed MASF consistently achieves superior or competitive makespan performance compared with baseline scheduling algorithms.