Six Sigma for improving tensile strength: a case study in the impregnating resin manufacturing company

Purpose Unsatisfactory level of construction materials quality has been a persistent problem for companies in construction. This study aims to describe the application of the Six Sigma methodology for improving the tensile strength in a Chinese reinforcement material manufacturing company. Design/methodology/approach Six Sigma-based framework of define-measure-analyse-improve-control (DMAIC) methodology is adopted in this case study. During different stages, quality problems and critical factors are identified to improve the low performance of tensile strength and thixotropy of the impregnating resin. Findings The results provide solid evidence that how Six Sigma can be successfully applied in reinforcement material manufacturing. Results showed that vacuum degree, reaction temperature and stirring rate are significant factors on tensile strength. Control plans for continuous improvements are suggested and implemented. Our study found that managerial assurance activities such as verification were less developed than equipment-related control activities. Besides, data management required further elaboration on integrated data and information systematically, thereby to enable the company to make informed decisions and to support continuous improvement. Originality/value This study contributes to show a potential area in which Six Sigma DMAIC approach can promote to improve the tensile strength of impregnating resin. This case can prompt managers of the company to apply Six Sigma method to address complicated problems in other reinforcement material processes. Companies of construction and their suppliers can refer to this study when improving their manufacturing process.