Mixed-model production system design for aircraft assembly

With the advancement of flexible fixture and flexible tooling, mixed production has become possible for aircraft assembly as the manufacturing processes of different aircraft/sub-assembly models are similar. However, due to the low volume and complex constraints of aircraft assemblies, how to model the problem and produce a practical solution has been a great challenge. To tackle this challenge, this work proposes a methodology for designing the mixed production system, and a new scheduling approach is proposed by using combined backward and forward scheduling methods. These methods are validated through a real-life industrial example. As a result, the number of workstations is reduced by 50%, and the cycle time for making a fuselage is reduced by 38% by using the new mixed-model system.