A multi-objective approach to the assignment of stock keeping units to unidirectional picking lines
CITATION: Le Roux, G. J. & Visagie, S. E. 2017. A multi-objective approach to the assignment of stock keeping units to unidirectional picking lines. South African Journal of Industrial Engineering, 28(1):190-209, doi:10.7166/28-1-1615.
The original publication is available at http://sajie.journals.ac.za
An order picking system in a distribution centre consisting of parallel unidirectional picking lines is considered. The objectives are to minimise the walking distance of the pickers, the largest volume of stock on a picking line over all picking lines, the number of small packages, and the total penalty incurred for late distributions. The problem is formulated as a multi-objective multiple knapsack problem that is not solvable in a realistic time. Population-based algorithms, including the artificial bee colony algorithm and the genetic algorithm, are also implemented. The results obtained from all algorithms indicate a substantial improvement on all objectives relative to historical assignments. The genetic algorithm delivers the best performance.