An Efficient Constraint Programming Approach for Solving the Multi-Workshop Facility Layout Problem

The multi-workshop facility layout problem (MWFLP) focuses on the optimal distribution and placement of departments across multiple workshops to maximize material handling efficiency and space utilization in manufacturing systems. This study introduces constraint programming (CP) techniques to the facility layout problem and proposes a multi-objective optimization framework to address the MWFLP. The model employs interval variables to accurately represent facility dimensions and integrates cumulative functions to rigorously enforce non-overlapping and spatial constraints. To improve computational efficiency, symmetry-breaking constraints are introduced to minimize redundant solution spaces and accelerate the search for better layout. The effectiveness of the CP model is demonstrated through comprehensive experimental evaluations, where it consistently delivers superior solution quality and computational efficiency compared to the mixed-integer programming model. In multi-objective optimization scenarios, the CP framework outperforms the multi-objective particle swarm optimization method, offering enhanced solution precision and stability across diverse problem scales.