买卖双方在货物交付和款项支付的过程中,都有履行合同各项规定的义务。这些条款往往反映了双方的共同利益,是在平等互利的基础上达成的。但也有一些是属于例外的。譬如,订购货物的数量和时间间隔等,则完全由买方抉择。本文试图为买方建立一个在允许延期支付条件下的经济批量的数学模型,并指出买方在订购货物时所应采取的经济订购策略。文章最后对模型作了一些简单的评述。 Both the buyer and the seller have the obligation to fulfill the stipulations of the contract in the process of delivery of goods and payment of money. These provisions often reflect the common interests of both sides and are reached on the basis of equality and mutual benefit. But there are some exceptions. For example, the number of goods ordered and the time interval, etc., is entirely determined by the buyer. This article attempts to establish a mathematic model for the buyer of the economic lot under the condition that the deferred payment is allowed and points out the economic ordering strategy that the buyer should take when ordering the goods. Finally, the article made some simple comments on the model.