The Rearrangement of Items in a Warehouse

This paper is concerned with finding the optimal way of rearranging items in a warehouse from their initial positions to their desired final locations. Such a rearrangement may become necessary because of changes in the relative demand for each item, with the result that what were once fast-moving items at the front end of the warehouse, are now only slow-moving ones that must be moved towards the “rear.” Although the problem, as treated in this paper, is addressed to the rearrangement of items in a warehouse, many other applications come immediately to mind, such as the reorganization of the layout of open-plan offices and factories. The paper gives a two-stage algorithm that produces the sequence of item movements necessary to achieve the desired rearrangement and incur the minimum cost (or time) spent in the rearranging process; the result is optimal in the restricted case where the rearrangement must be done in a number of cycles each one being of a short time duration (the case, for example, if the warehouse were to remain operative during the rearrangement).