全球化的商業環境加速產品更新，並且縮短產品生命周期。目前工業面臨著多樣化之挑戰，自產品設計、原料供應、中間部件製造、到最後商品的完成，每個環節皆與垮國公司相關。縮短產品生命周期與多樣化會把模糊不確定性和隨機不確定性一起帶入產品的製造過程中，因此在模糊性和隨機性共存於現代的製造業環境之下，為尋求顧客的高滿意度與市場的更大佔有率，必需調整品質控制的方法。本研究的主要目的，以可信測度理論為基礎，探討在隨機模糊環境中品質管制圖建構的問題。關鍵設備的投資可以為企業帶來競爭力與盈利。面對投資決策時，經理人在解決多準則決策分析，多準則決策問題時常使用語意變數來評估。本篇研究主要展示利用模糊語意變數來進行關鍵設備投資決策的方法。透過實際案例，利用三角模糊數找出評估每個方案與標準的權重，進而評比各投資方案。關鍵設備的評選主要由三個決策人員來進行，共計三個設備評選方案與九項標準評估（分為三類：成本，效益性和有效性），透過模糊偏好關係的程度，來進行投資方案的排序。研究結果顯示，BMI真空爐是一個最佳的投資，而其投資順序分別是A1，A2，A3。

Investment in competitively advantageous critical equipment can be profitable for companies. For such investment decisions, managers tackle multi-criteria decision analysis and multi-criteria decision-making problems using linguistic variables. This work applies the fuzzy linguistic variable approach to the decision-making of a critical equipment investment and demonstrates the approach through a numerical example, where the ratings of each alternative and the weightings of each criterion are expressed as a triangular fuzzy number. The proposed approach involves three decision-makers, and three alternative equipment candidates are evaluated based on nine criteria (classified into three categories: cost, benefit, and efficacy) by calculating the final fuzzy preference relation and creating a stepwise ranking procedure. The results of this study indicate that a BMI vacuum furnace would be the most beneficial investment. The ranking of the three alternatives is A1