Product placement within a fast-picking tunnel of a distribution centre

Abstract

This investigation emanated from the concern of management of a distribution centre (DC) in the beverage industry that a fast-picking tunnel was severely congested during peak-picking season. They were interested in finding out whether the placement sequence of stock-keeping units (SKUs) has an impact on throughput/performance. The objective of this investigation was to optimise the placement order of products in the fast-picking tunnel of a DC to reduce congestion and improve throughput. To minimise the total restocking effort, the number of pick locations for each product picked was first optimised. A simulation model was then built to evaluate the queuing of a given product placement strategy in the fast-picking tunnel (forward pick line). Finally, the performance of the following product placement strategies were evaluated: current strategy, probability low to high, probability high to low, volume low to high, volume high to low, probability × volume high to low, probability × volume low to high, probability bowl and volume bowl. The sequencing probability low to high sequence was the best placement strategy followed by the volume bowl and probability bowl sequences. The gap between these sequences reduces as the arrival rate in the forward pick area increases. Practitioners seem to prefer the bowl sequences over the probability low to high sequence because of the need to build a solid pallet base. Therefore, the industrial sponsor preferred the volume bowl sequence for implementation.