在黏貼型紙尿褲的製造程序中,生產設備常會隨著時間的變動而慢慢退化,若置之不理,導致產出不良品之比例也隨時間變動慢慢遞增。如此將造成生產成本增加、影響存貨水準以及使得總利潤降低,甚至可能因為顧客抱怨導致企業形象受損等。因此,企業可考慮在生產的過程中,進行預防性的維護保養,以確保產品品質。然而維護保養頻率過高,將使得維護成本增加;反之,過少或不做維護保養可能讓不良品比例隨時間累積遞增,甚至可能因為設備因缺乏保養而故障,造成停工的損失。本研究以製造黏貼型紙尿褲為例,探討具不完美製程的生產維護與庫存管理問題,並據此建立含不良品且考慮維護保養的經濟生產批量(Economic Production Quantity, EPQ)模式。主要目的在於決定最適的維護保養頻率、生產與補貨週期長度,以使得單位總利潤有最大值。進一步,我們利用幾個較符合實務的數值範例說明求解的過程,並對模式中的參數進行敏感度分析,根據數據分析的結果賦予一些管理的意涵,期望能提供決策者擬定相關政策之參考依據。
In the manufacturing process of adhesive diapers, the production equipment often degrades slowly with time. If left unattended, the proportion of defective products produced will gradually increase with time. This will increase production costs, affect inventory levels and reduce total profit, and may even damage the corporate image due to customer complaints. Therefore, enterprises can consider preventive maintenance during the production process to ensure product quality. However, the frequency of maintenance is too high, which will increase the maintenance cost; on the contrary, too little or no maintenance may increase the proportion of defective products over time, and may even cause the loss of downtime due to equipment failure due to lack of maintenance. This study takes the manufacture of adhesive diapers as an example to discuss the problems of production maintenance and inventory management with imperfect processes, and accordingly establishes an economic production quantity (EPQ) model that contains defective products and considers maintenance. The main purpose is to determine the optimal maintenance frequency, production and replenishment cycle length, so that the total profit of the unit has a maximum value. Further, we use several practical numerical examples to explain the solution process, and perform sensitivity analysis on the parameters in the model. According to the results of the data analysis, we give some management implications, and we hope to provide reference for decision makers to formulate relevant policies.