Abstract
We consider a low level picker-to-parts system in a one-block warehouse with P/D point located at a corner point. We develop new and exact analytical models to estimate travel distance for random, full turnover and class-based storage in which a single picker follows an S-shaped traversal routeing policy. Our analytical results for random, full turnover and class-based storage follow corresponding simulations very closely with an accuracy of within 2% for the range of warehouse parameters considered. We also report the percentage improvement obtained by the optimal 3-class storage strategy over the random storage policy and the potential gain of this 3-class policy as compared to the full turnover policy. Further, we conduct a computational study to determine the optimal layout parameters for a warehouse with a 3-class optimal storage strategy for a given pick size per tour. Sensitivity analysis of pick travel distances with important warehouse parameters is also presented.
Acknowledgements
The authors are thankful to two anonymous reviewers for their comments which improved the quality of the paper.