اثرات تورم در ارزش زمانی پول در مدل مقدار سفارش اقتصادی با چرخه تصادفی عمر محصول

For several decades, the Economic Order Quantity (EOQ) model and its variations have received much attention from researchers. Recently, there has been an investigation into an EOQ model incorporating a random product life cycle and the concept of time-value of money. This paper extends the previous research in several areas. First, we investigate the impact of inflation on the choice of replenishment quantities. Second, the unit cost, which has been inadvertently omitted in the previous research, is included in the objective function to properly model the problem. Third, we consider the normal distribution as a product life cycle in addition to the exponential distribution. Fourth, we develop a simulation model which can be used for any probability distribution.

The Economic Order Quantity (EOQ) model initiated by Harris [13] has been extended many ways to improve the practicality of the model. See, for example, [3] and [4], etc. One of the important extensions is to properly recognize the time-value of money in determining the optimal order quantity. Trippi and Lewin [21] have adopted the Discounted Cash-Flows (DCF) approach for the analysis of the basic EOQ model. Kim et al. [14] extend Trippi and Lewin's work by applying the DCF approach to various inventory systems. Chung [5] has studied the DCF approach for the analysis of the basic EOQ model in the presence of the trade credit. Recently, Haneveld and Teunter [11] apply the DCF approach to the basic EOQ model with a Poisson demand process.

As pointed out by Silver [19] in his review, if the quantitative models are to be more useful as aids for managerial decision-making, they must represent and formulate more realistic problems. This paper has been motivated by the need for such problem formulation, and we have investigated the effect of inflation and time-value of money in an EOQ model with a random product life cycle. It is worthwhile to note that the optimal cycle length may be very insensitive to inflation in the presence of discounts because the breakpoint value is often the best order quantity over a wide range of parameter values [8].