Application of Lean Six Sigma for yield improvement in the stainless steel industry: a recipe from Türkiye

Abstract

Purpose This study aims to demonstrate the application of Lean Six Sigma (LSS) at a stainless steel manufacturer in Türkiye for yield improvement. Design/methodology/approach A qualitative approach consisting of a single descriptive case study was adopted. Both primary and secondary sources were used. The interviews were conducted with the Six Sigma team. In addition, an in-depth review of the project documents was conducted. The “define, measure, analyze, improve and control (DMAIC)” phases were explained by examining the tables, facts and figures. The company’s downgraded rate owing to defective materials was 0.21%. Root causes were detected in the tension unit, carpet cleaning, coating unit, film surface and cleaning of the rolls. Therefore, improvements were taken accordingly. Findings The rolled throughput yield was 99.05%, and the defect rate was reduced to 0.08% after implementing LSS, which provided statistically proven results and a direct reflection on customer satisfaction. Originality/value To the best of the author’s knowledge, this is the first case study examining the application of LSS to improve the yield of a medium-sized stainless steel company in Türkiye.