Travel-energy models for a low level picker-to-part system

Abstract

Material handling is major activities in warehouse operations and represents between 15 and 70 percent of the total cost of a manufactured product. Depending on the type of warehouse, it is reported that 30 to 40 percent of warehouse labor costs are incurred by the picking operation. Especially, in low-level picker-to-part system, the picker performs the retrieval of items on the pick list and the order picking processes consumes more than half of the total operating costs for typical warehouses. Therefore, the decision on stock locations in a distribution warehouse is an important concern in terms of the material handling cost and the work-load of the order picker. Several papers addressed the stock location problem in a warehouse with the objective of assigning items to storage locations to minimize materials handling cost. But, all these studies mentioned did not consider the effect of the weights on material handling costs and assumed that the cost of moving an order of any item from particular location to the shipping area depends only on the distance, regardless of the item type handled. So, weight of item should be incorporate into the cost in our research. Also, human safety should be incorporated into the cost, particularly when the handling operations are carried out manually. So, we recently proposed a criterion, called the density-turnover index (DTI) rule integrates the weight into the COI rule. This paper introduces DTI based travel-energy models for a low level picker-to-part system advanced Hwang’s paper. The DTI based travel energy model appears to be another practical solution technique for its simplicity and easy implementation in real world application.