Competitive advantage through Six Sigma in sand casting industry to improve overall first-pass yield: a case study of SSE

Purpose The purpose of this paper is to illustrate how Six Sigma methodology has been applied in a small-scale foundry industry to improve the overall first-pass material yield and quality, with a view to the product and the process. Design/methodology/approach The researchers have reported this paper based on a case study carried out in industry using the Six Sigma Define, Measure, Analyze, Improve and Control (DMAIC) and its application in improving the manufacturing process of a foundry shop. Findings Identified root causes are validated and countermeasures are implemented for improvement. As a result of this case study, the overall first-pass yield of the sand casting process is improved to 78.88% from the previous yield of 67%. For product-specific case, yield is improved by 18% through the improved gating system design. Sigma level of the process is improved to 3.08 from baseline 2.21. Key lessons learned from this case study are mentioned in the current study. Research limitations/implications This case study provides a standard road map and motivates small-scale foundry industries to implement Six Sigma methodology for productivity improvement, especially in jobbing foundry. The presented paper is based on a single case study, and the results are limited to the company only. Also, one of the reasons for low process yield is slag creation, which is not covered here, as it is a concern of the material quality supplied by the vendor. However, the approach of this paper is generic for learning perspective. Practical implications This case study provides a standard road map and motivates small-scale foundry industries to implement Six Sigma methodology for productivity improvement, especially in jobbing foundry. Through the effective application of Six Sigma quality initiative, how a quantum jump in financial aspect could be gain, has been demonstrated. Originality/value This research study showcases step-by-step implementation of Six Sigma-DMAIC methodology at a small-scale foundry industry. This paper could serve as a unique roadmap for practitioners and academicians to improve the material productivity of the foundry industry both ways, product and process.