| Abstract: | This paper shows, through an alternative development of the lot size model, how the methods of capital budgeting can be logically applied to the determination of optimal inventory levels. There is no reason why inventory management needs be treated any differently than the management of fixed assets. The rule that the stock of fixed assets should be expanded until the marginal rate of return equals the marginal cost of capital results from maximizing the present value of profits as a function of the investment level. In a like manner, the “square root” formula from inventory theory results from maximizing the present value of profits as a function of the investment in inventory. In addition, formulating the inventory problem as a capital budgeting problem has advantages for incorporating deterioration, obsolescence, and other costs into the model in a more logical and less intuitive way. |
