線性規劃應用於生產改善之研究 以某輪胎內胎生產廠為例

Applying Linear Programming in Production Improvement of Tube Manufacturing Factory

許展鳴(Chan-Ming Hsu)

指導教授 ： 梁直青

國立虎尾科技大學/管理學院/企業管理系經營管理碩士在職專班/碩士(2016年)

摘要

在輪胎產業，市場需求已經明顯的改變，競爭變得異常激烈，尤其是來自中國的競爭，因此降低成本對於輪胎業的生存是至關重要的。而成本的優勢需從順應市場環境而改變生產管理與流程的方式去執行，進而降低成本和獲取利益。
輪胎業不僅需要在產品的價格上有所競爭力，也要滿足顧客的需求並生產各種客製化商品，導致生產必須趨向少量且多樣化。也因為如此輪胎業為了能滿足消費者的需求又要讓生產成本最低，透過精實生產可以徹底地消除無附加價值的浪費並大幅提升整個公司或工廠的生產效率。但是依靠經驗資料解決問題不夠細膩、不夠合理，有時與實際情況常不相符合，產業的不同而產生差異與成效不佳。所以運用科學的方式安排生產，利用現代化的工具，採用定性分析和定量分析相結合的方法，同時一切管理工作都要做到定量化、最優化，才能夠有效的降低生產成本，而線性規劃理論就是合理利用、調配資源的一種應用數學方法。它的基本思維就是在滿足一定的限制條件下，使預定的目標達到最佳化。它在輔助各項決策、計畫優化等方面具有重要的作用，是系統工程學和現代管理科學中的一種基礎理論和不可缺少的方法、手段和工具。
此研究主要以A公司台灣廠內胎生產廠自行車內胎生產前段押出工程為主，目前該內胎生產廠前段押出工程總共有5條生產線，共生產四種產品，其中4條生產線為自行車內胎押出生產線，另一條為機車內胎、輕型卡車內胎及工業用車內胎押出生產線。A公司自行車內胎押出每日產量約54000條，分兩班制生產。近幾年隨著自行車運動興起，使得自行車內胎的需求由大批量生產轉成少量多樣生產，但局限於設備限制，如何有效率的滿足後工程(加硫工程)需求，就需要合理地安排現有的人力、設備等資源去完成生產任務，使產品如期出貨。
透過線性規劃的數學模型，將生產規格(厚度)及需求數量設為自變數，最佳生產配置時間為應變數，將其部分生產因素設定為限制式，運用所建立的模型，將每班生產(半日)必須生產的規格與數量，經由數學模型計算後，得知生產規格與數量的生產配置，並依據結果進行生產。搭配TPS(Toyota Production System)精實生產消除浪費概念與流線化生產建立架構於某輪胎業的內胎廠的現場生產流程，目的是該公司的內胎廠在推動精實生產管理時，透過線性規劃模型可以讓生產管理者可以知道每日的生產所需數量，並且用最少的時間來進行生產，也可以給生產計畫人員能透過模型可以在與業務單位於接單後排定生產計劃前能進行預估交期，進而從生產規劃掌控生產時程與效率。

關鍵字

線性規劃 ； 精實生產 ； TPS(Toyota Production System) ； 輪胎 ； 內胎

並列摘要

In current tire industry, market demand has changed prominently and competition, especially from China, has become extremely fierce. Therefore, decreasing cost is vital for a company to survive in tire industry. To obtain cost advantage, it is necessary to conform to market environment and to change production management and processes, which resulted in cost deduction and profit earning.
Tire industry needs not only to be competitive in product pricing, but also to meet customers’ demand by customization of various products. As a result, tire companies are prone to a small amount of production but with diversity. In order to satisfy demands from consumers as well as to decrease cost to minimum amount, tire industry can completely eliminate waste without value-added, and also improve production efficiency in companies or factories substantially by lean production. Nevertheless, solving problems based on past experience and data is not delicate and rational, and sometimes not consistent with reality due to diverse industry and poor performance. Effective production cost reduction can be achieved by arranging production in a scientific way, utilizing modern tools, adopting combined methods of qualitative analysis and quantitative analysis, and meanwhile managing all tasks quantified and optimized. Linear programming planning is an applied mathematics methodology to reasonably utilize and allocate resources. Its basic principal is to achieve maximum performance for planned objectives under certain constrained conditions. It can be in aid of decision making and plan optimization, and is a fundamental theory and an indispensable way, means, and tool of Systems Engineering and modern Management Science.
This research studies bicycle inner tube production line in A company in Taiwan, specifically for extrusion process in front end of production line. The tube factory currently has 5 production lines in extrusion process to manufacture inner tubes for bicycles, motorcycles, trucks, and industrial vehicles. Out of 5 production lines, 4 lines are set for bicycle inner tubes, and 1 line is for the rest of vehicles’ inner tube manufacturing. Daily production capacity of bicycle’s inner tube in A company is 54,000 units, by 2 shifts. In recent years, due to rising trend of cycling, demand for bicycle’s inner tubes shifts from bulk production to small-volume large-variety production. Nevertheless, because of facility limitation, to meet back end of production line (vulcanizing process) efficiently, it requires to arrange existing man power and equipment reasonably to complete production tasks and deliver products on schedule.
With assistance of mathematic models of linear programming, set production specification (thickness) and demand quantity as independent variable, optimum production time as dependent variable, and partial production factors as limited. Using this mathematically structured model, one can calculate production specification and demand of half day per shift, and thus gain production arrangement for manufacturing according to gained result.

並列關鍵字

linear programming ； lean production ； TPS(Toyota production System) ； Tire ； Tube

參考文獻

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