Self-reconfiguration and rescheduling of aero-engine assembly shop with rework disruption in knowledgeable manufacturing environment

An aero-engine has to be assembled twice or more to satisfy stringent technical standards. Substandard engines are required to re-enter for additional reassembly, which may trigger rework disruption. Work groups with flexible skills are responsible for the operations and can be reassigned when rescheduling triggers. An integrated problem of rescheduling of engines and reconfiguration of work groups with rework disruption is formulated here. A heuristic is proposed to solve the problem. In self-reconfiguration optimization, work groups are reassigned in accordance with the workload balance criterion without violating the assembly skills constraints. In rescheduling optimization, locally optimal sequencing propositions of operations are derived and applied to generate a feasible schedule. Three neighborhood structures are defined, and a variable neighborhood search is implemented to optimize the assignment and the schedule of operations on parallel work groups. The effectiveness of the proposed algorithm is tested by several numerical experiments. The results show that the proposed algorithm promises apparently lower total cost and more desirable assignment of work groups by scheduling.