Abstract
The Assembly Line Part Feeding Problem (ALPFP) is a complex combinatorial optimisation problem concerned with the delivery of the required parts to the assembly workstations in the right quantities at the right time. Solving the ALPFP includes simultaneously solving two sub-problems, namely tour scheduling and tow-train loading. In this article, we first define the problem and formulate it as a multi-objective mixed-integer linear programming model. Then, we carry out a complexity analysis, proving the ALPFP to be NP-complete. A modified particle swarm optimisation (MPSO) algorithm incorporating mutation as part of the position updating scheme is subsequently proposed. The MPSO is capable of finding very good solutions with small time requirements. Computational results are reported, demonstrating the efficiency and effectiveness of the proposed MPSO.
Acknowledgements
The authors greatly appreciate the collaboration of Volkswagen Navarra, the department of logistics in particular, as well as the Volkswagen Chair Universidad de Navarra for partially funding this research. The authors would like to thank Prof. Dr. Nils Boysen from Friedrich Schiller University Jena for his valuable comments and suggestions to improve the quality of the paper.
Notes
1. Tow-train capacity is transformed into tour capacity by adding the capacity of all available tow-trains. Thus, here and hereafter, when referring to capacity limits, tour and tow-train will be used interchangeably.
2. Hereafter, we will use priority rules or heuristic interchangeably.