One of the issues that arise with spare parts management in every industry is the management of excess parts. This is particularly so with engineering spares, used to provide operational support to maintenance and production.

With these spare parts, there are often a high number of items that are used only infrequently but which may be needed on short notice or deemed critical. Companies hold these items with an expected maximum-minimum holding of 1-0. That is, the company plans to hold only one item in stock and then order another one when they use that one.