年度生產決策規劃 - 以銅合金公司為例

本研究以某生產銅合金的公司為分析對象，幫個案公司以科學的方法建立一套線性規劃模型，求解個案公司在生產線產能與各種存貨限制下的年度最適生產計畫，以求生產成本極小。當某公司的產線有多種產品要生產，如果沒有明定的生產順序，一般而言，現場會選擇生產流程較容易的產品先生產，或者現場主管憑自身經驗，推估未來可能的市場需求來做產線安排。但這些決策往往缺乏科學基礎，所以經常造成某種產品產量過多或不足的情形發生，與此同時也就會導致人力成本及倉儲成本的無謂損失。透過線性規劃，產線的安排必須先滿足每個月的訂單需求，在淡季時如有閒置產能，則可以增加產量納入庫存，以備旺季時產線無法因應過多訂單需求時之需。目前現況中，個案公司分條及包裝部門一年生產成本高達7億1,604萬台幣，若以本研究的線性規劃求解下，總成本可降低為6億3,113萬台幣，節省的金額來自於產量的減少，意謂著產品本身的原料、人力支出、包材、製程相關費用的減少。而人力工時整年度可從原本122萬分鐘減少至106萬分鐘。產出數量也從原先555捲，降低到486捲，達到安全庫存量的範圍內，不僅降低生產成本，也減輕公司的存貨成本、倉儲空間和人力管理上的壓力。綜合以上，本研究貢獻在於設計一套簡易方便的模型，可明確訂定年度生產計劃表，依照計畫表事前可先安排人力班表，人力不足時預先知會委外加工廠商支援，降低產線的不穩定性發生，順利出貨滿足顧客需求，增加公司的營收。

關鍵字

線性規劃；產品產出配置

並列摘要

This study proposes a scientific approach to building a linear programming model for a copper alloy manufacturing company. It aims to offer an optimal annual production plan to minimize production costs, taking into account the constraints of production capacity and inventory. Without a stipulated production schedule, workers would generally choose products with simpler production processes to produce, or alternatively, the on-site supervisor would arrange production lines by forecasting future market demand based on his/her experience. However, these unscientific decisions always result in either over- or underproduction, which in turn leads to unnecessary labor and storage costs. According to linear programming, the arrangement of production lines must first fulfill the monthly order requirements. If there is idle capacity during low seasons, then production could be increased to build up inventory for peak seasons when there may be too many orders to handle. The company’s slitting and packaging departments presently have a production cost of up to NT$716.04 million. If linear programming is adopted as suggested in this study, the total cost could be lowered to NT$631.13 million. The savings would originate from reduced production, which implies reduced expenses in raw materials, labor, packaging materials, and production processes. Annual labor time decreases from 1.22 million minutes to 1.06 million minutes, whereas production also decreases from 555 rolls to 486 rolls, which is still within the safe inventory range. This not only reduces production costs, but also alleviates the company’s stress in personnel management, and the cost of inventory space. To summarize, this study designed a simple and convenient model for setting up a clear annual production plan, which can be used to prepare a work schedule ahead of time. This allows process outsourcing to be considered in advance when there is a labor shortage, lowering the instability of the production, maintaining product supply, satisfying customers’ needs, and simultaneously boosting the company’s revenue.