| 摘要: | 六標準差以顧客需求導向為重心，藉由了解顧客需求進行改善，不僅可以消除變異、降低成本，並同時能提升顧客服務品質、滿意度，亦可以為企業提升效能、績效與獲利等實質效益，其顯著之成效為六標準差至今仍被各領域廣泛應用之原因。本研究以C公司為例，藉由六標準差之手法進行錫球批退率之研究，以DMAIC之步驟找出問題之根本原因，並擬定對策進行改善，最後進行文件標準化，藉以改善錫球批退率。
於定義階段，藉由蒐集顧客聲音、了解顧客之需求，找出關鍵品質特性並量化欲改善之目標，並使用SIPOC流程圖，釐清供應商與顧客之間之對應關係。於量測階段，定義量測計畫，並分析量測系統，確認量具之一致性，接著確認現有之製程能力，並定義績效目標。於分析階段，主要為分析變異來源，確認造成錫球之原因，並針對造成錫球之原因進行改善，並使用3WHY分析搭配柏拉圖篩選出真因，並針對真因進行改善。於改善階段，針對需改善之項目進行改善，擬定可行之對策，確認是否有成效，並使用假設檢定確認是否確實有效。最後於控制階段，將改善對策標準化，以維持改善後之成效。
其改善後之成效，使錫球批退率大幅降低，並節省重工成本，亦同時增加顧客滿意度。經本研究之結果說明六標準差不僅能改善品質，亦能降低重工成本、節省人員重工工時，降低變異及浪費，並能使用其手法及工具平行展開用於改善其他需改善問題之處，得到事半功倍之效果。
;Six Sigma focus on demand of customer. Via understanding customer’s needs and making improvements, it can not only eliminate variability and reduce costs, but also enhance quality of customer service and satisfaction. It’s also can improve efficiency, performance and profitability for the company. The well effectiveness of improvement is the reason why Six Sigma are still widely used in various fields.
This study take C company as an example to study the rejection rate of solder balls by using the method of Six Sigma, and find the root cause of the problem with the steps of DMAIC. Then take actions for improvement, and standardize the documents to improve the rejection rate of solder balls.
In Define stage, we collect voice of customer (VOC), understand key customer requirement, identify critical to quality (CTQ) and quantify the goals that need to be improved, and use the SIPOC chart to clarify the relationship between suppliers and customers. In Measure stage, we define the measurement plan first, using the measurement system analysis (MSA), confirm the consistency of the measurement tools. Then we confirm the process capability and define the performance target. In Analysis stage, the main purpose is to analyze what’s the main reason that cause solder balls, and focus on the problems that cause solder balls. Then we use 3WHY analysis and Pareto Chart to confirm the root causes, and improve them. In Improve stage, we improve the items that need to be improved, formulate and implement corrective actions, and verify the effectiveness of corrective actions. Then we use hypothesis testing to test the significance level. At last, in Control stage, we standardized corrective actions to maintain the effectiveness of the improvement.
As a result of the improvement, the rejection rate of solder balls was reduced and saved rework costs. The results of this research show that Six Sigma can not only improve quality, but also reduce rework costs, save waste of rework man-hour, and can use this method and tools to improve other processes that need to be improved. The effect of getting twice the result with half the effort. |
