Economic Order Quantities with Inflation

The classical EOQ formula assumes that all relevant costs and prices are constant. In this paper it is shown that with inflation the choice of the inventory carrying charge used in the EOQ formula depends on the company's pricing policy. If prices change independently of replenishment order timing the inventory charge should be low and independent of the inflation rate. However, when no "double ticketing" is permitted and the company uses a constant percentage mark up the carrying charge is high and depends on the inflation rate and the mark-up. Only if the company is allowed a fixed monetary margin is the classical result for carrying charge valid.     

有供应方限制的临时价格折扣与最优存贮模型

供应方提供临时价格折扣，一般都附带特别定货量限制。购买方可在所提供折扣价格条件下从有限种订货量中选择最小的订货量，但不一定是最优订货量。本文提出有供应方限制的临时价格折扣条件下的最优存贮模型和订货策略。并给出应用实例。     

A Note on Determining Order Quantities with a Linear Trend in Demand

The economic order quantity concept has received much attention. However, the model is severely restricted by the assumption of constant demand. This paper presents a procedure for adjusting the economic order quantity model for the cases of increasing or decreasing linear trend demand patterns. The primary advantage of the proposed method is its simplicity in comparison with existing procedures and, as illustrated in two examples, its near-optimal performance     

The Effect of the Timing of Disbursements on Order Quantities

This paper looks at the effect that the timing of disbursements may have on order quantities. Traditional analyses for determining order quantities assume that all disbursements are made at the same point in time. In this paper it is shown that large timing differences may significantly affect order quantities. Firms operating in these environments may want to adjust their order quantities accordingly.     

On the Joint Calculation of Safety Stocks and Replenishment Order Quantities

It has been well established that for optimum operation of a re-order level policy, re-order levels and replenishment order quantities should be jointly calculated. There exist many solutions to this stock control problem. A number of these involve approximations which simplify the mathematics of the problem but yield non-optimal solutions, while others raise the question of whether the additional computational effort required, due to mathematical complexity, is economically justified.This paper describes that if the lead time demand can be considered as normally distributed and lead time is constant, then it is possible to arrive at optimal values of safety stocks-consequently re-order levels-and order quantities, with minimum computational effort, through a nomogram which accomplishes a major part of the necessary computations.The flow chart of a program that can make the calculations is also presented.     

Effect of Delayed Payments (Trade Credit) on Order Quantities

We address the problem of determining the economic order quantity when the vendor permits delay in payment. Some early researchers argued that the best order quantity is invariant with respect to the trade credit. Others argued that the order quantity should increase as the delay in payment increases. We analyse this problem using the discounted cash-flow approach, and provide clarification on the inconsistencies between these approaches. First, we show that the best order quantity is an increasing function of the permitted delay in payment. We also show that an approach suggested by Chand and Ward not only yields an upper bound on the optimum, but also provides robust results. Though the classical square-root formula disregards trade-credit information, under some circumstances, it will yield better results than the formulation taking into account that information. We illustrate this anomaly with an example, and provide analytical explanation for it. We also discuss some potential conceptual pitfalls in using the average cost analysis as an approximation to the discounted cash-flow approach.     

考虑需求率变化与延期支付的临时订货模型

供应商给予临时价格折扣、并针对采购商的临时订货给予优惠的延期支付条件;同时考虑到采购商的自身需求即为终端需求并对价格敏感,由于考虑需求量变化的同时考虑到时间因素,因此需求率实际上发生了改变。在这样的背景下,采购商在价格变化时刻面临两种选择:以低价购进大量货物或者放弃这个机会。本文以EOQ模型单位产品成本为参考,从成本节约最大的角度出发,分析了采购商临时订货量的确定过程,并用数例分析了参数变化对最优订货以及成本节约情况的影响。     

The Calculation of Order Quantities and Protection Levels in a Re-Order Level Stock Control System

A rapid iterative procedure for calculating order quantities and protection levels is described and attention drawn to an error in a fundamental paper.     

与P矩阵和LCP有关的量(英文)

发展了与P矩阵有关的基本量的一些新性质,并且改进了由Xiu和Zhang[A characteristic quantity ofP-matrices,Appl.Math.Lett.,2002,15:41-46]提出的水平线性余问题全局误差上限.     

焦点量与鞍点量的关系

对于一般情形,给出焦点量和鞍点量计算与约化的Maple算法,从而统一了焦点量和鞍点量的计算,并给出细焦点与细鞍点的变换,利用变换推导了焦点量和鞍点量的关系．     

焦点量与鞍点量的关系

对于一般情形,给出焦点量和鞍点量计算与约化的Maple算法,从而统一了焦点量和鞍点量的计算,并给出细焦点与细鞍点的变换,利用变换推导了焦点量和鞍点量的关系.     

Reductions between meager ideals

We construct a nonmeager ideal that is not a P-ideal yet Fin × ⊘ is not reducible to it. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 11, No. 4, pp. 213–219, 2005.