無限規劃期下，產品需求率固定且所有需求皆必須滿足；不同的產品有不同的整備時間及整備成本，此整備時間及整備成本僅與該產品有關連，與製造順序無關聯；單位產品每單位時間之存貨持有成本固定；單機器於同一時間只能用於生產單一產品的多產品生產規劃問題被稱之為經濟批量排程問題(Economic Lot Scheduling Problem, ELSP)。經濟批量排程問題可經由降低生產速率來減少存貨成本，進而得到較低的總成本。本研究之兩產品經濟批量排程問題所採用的降低生產速率方式為彈性速率法(Flexible Approach)，除了必須滿足上述經濟批量排程問題之基本假設外，另假設於倉儲空間有限、有多餘產能可採用彈性速率法、產品每次生產之批量固定，且產品開始生產的時間為存貨降至零之時開始生產，在這些條件之下決定出兩產品的生產週期長度，目標為最小化每單位時間總成本，稱此問題為『倉儲受限下可變動生產速率之兩產品經濟批量排程問題』。
本研究得出兩產品在倉儲有限下，應用彈性速率法後之最佳求解政策必為共同週期法。數值分析部份，比較了兩產品倉儲受限不同模型間之成本，本研究所採用之模型除了有較低之成本外；於廠商執行運作時也比較容易，另分析了不同參數值對模型之影響。於多產品方面，不論整備時間及整備成本是否與製造順序有關聯，得出在倉儲有限下應用彈性速率法之經濟批量排程問題，不存在機器閒置時間的性質；給定任一生產排序，證明出倉儲受限下可變動生產速率之經濟批量排程問題，最大總體積發生在某一產品以最大速率結束生產之時，此性質有助於多產品模式之建立。

The problem which considers a single facility dedicated to the production of several different items is well known as the Economic Lot Scheduling Problem (ELSP). The objective of this problem is to find a schedule to minimize the setup costs and inventory holding costs while satisfying the static demand of all items. Traditionally, the production rate of the machine was chosen according to its maximum capacity. In recent years, it has been suggested that the manufacturer can make good use of the machine idle time by reducing production rate. Reducing production rate will lead to lower inventory holding costs, and hence the total costs. In this research, we will adopt the flexible approach to take up the machine idle time. Sometimes manufacturers have to decide the production quantities and schedules under some constraints. Warehouse space constraint is one of them that manufacturers might encounter. We consider the case where two products are required to be produced in a single facility with warehouse constraint. Assume that the machine has idle time to use flexible approach. The objective of this research is to determine the optimal production quantities.
This study obtained the following propositions: 1. Common cycle approach is the best production policy for two products warehouse constrainted ELSP using flexible approach. 2. In the aspect of multiple products, it does not exist machine idle time in the optimal solution of warehouse constrainted ELSP using flexible approach. This property also holds for sequence dependent setup time and setup cost ELSP. 3. The maximum volume of inventory occurs at the time that the machine stops producing a product at its maximum rate. This property is helpful for the formulation of the ELSP.

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