Obsolescence of Commodities which are Subject to Deterioration in Store

When the useful life of a commodity in the field (“the field life”) is affected by the time the commodity spends in store prior to issue (“the store-age”), it is necessary to assess under what conditions goods become obsolete in the store before they are issued. Other problems of interest are: What is the total useful field life expected from a given stock-pile and what is the optimal quantity of goods that should be ordered? These problems are discussed for three cases: 1. A stock-pile of identical units 2. A stock-pile of non-identical units 3. A stock-pile of several batches of components. It is further shown that the last case is a general model, from which the first two and several other special cases may be derived.