In many large-scale inventory systems, a large percentage of the stock investment is tied up in items that have been designated as repairable, presumably because economic tradeoffs favor rapair over disposal and replacement. In this system there are two distinct inventories, the inventory of items ready-for-issue, and the inventory of repairable carcasses.
The paper develops lot size systems for the repairable items in which demand, production, and repair rates are constants with the constant and the varying rates of attrition. Contrary to the previous work done, two decision variables are introduced in the models, a discreste variable and a continuous variable each representing the time to repair and the amount to be produced or procured respectively.
Numerical method is applied to find the optimal solution of the developed models when the closed form of solution does not exist.
