以精實六標準差模式探討不鏽鋼線材生產缺陷之研究

近年來因不鏽鋼市場供需及趨上升，以及面對下游廠商對於盤元品質及交期，日漸嚴苛，以及營業價格，藉能滿足客戶要求與期望。本研究利用精實六標準差的改善作法，從根源找出其中影響盤元品質要素，亦分析出從中製程改善作法來進行作業，並成立專案團隊，經由數據分析及現場實際作業，從中改善。利用六標準差改善手法，定義、衡量、分析、改善、控制，進行一系列分析改善作業，並找出其中影響影響盤元刮痕主要要因，從中改善盤元刮痕主要關鍵要因，藉由改善階段數據分析下，並分成第一階段以及第二階段進行。第一階段由精軋機前段進行改善，盤元刮痕率由10.0%降至5.0%，影響噸數由26.87噸降至17.74噸，第二階段由精軋機後段進行改善，盤元刮痕率由5.0%降至0.93%，影響噸數由14.74噸降至2.48噸，利用六標準差成功提升盤元品質，已達到個案公司未來生產競爭力目標。

關鍵字

精實六標準差； DMAIC ；刮傷；製造改善

並列摘要

In recent years, due to the rising of the supply and demand of stainless steel and the harder request of quality and time of delivery from downstream firms, improving manufacturing process is needed to satisfy requirements and expectations from customers. In this study, a project group is formed to find out the key factors affecting coil quality and to improve the process, with the consequence of data analyzing and manufacturing experience, using lean six sigma method. To figure out the main causes of scratches on coils, we made a sequence of data analyses by following the steps of six sigma: Define, Measure, Analyze, Improve, Control (DMAIC). The process improvement based on the former analyses is applied in two phases. In the phase one, we focus on the manufacturing improvement of the front-end of Finish Block, and the scratch rate of coils decrease from 10.0% to 5.0%. The weight of scratched coils decreased from 26.87 tons to 17.74 tons. In the phase two, we improve the manufacturing process of the back-end of Finish Block. The scratch rate decrease from 5.0% to 0.93%. The weight of scratched coils decreased from 14.74 tons to 2.48 tons. We succeeded in enhancing the coil quality by applying six sigma, reaching the target of raising the future manufacturing competitiveness of the case-study company.