Integrating Theory of Constraints, Lean and Six Sigma: a framework development and its application

Abstract

This paper presents an integrated framework that combines the strengths of three relevant business excellence philosophies: Theory of Constraints, Lean, and Six Sigma (TLS). The integrated framework increases the TLS Orientation of a firm when management employs a unique growth-oriented mindset, adopts global measurements, and implements an integrated continuous improvement methodology. We discuss how a small-to-medium enterprise (a real but disguised manufacturing firm in India) implemented the proposed framework by employing the cognate key concepts and tools in an integrated manner, and improved its business excellence in terms of improved flow, reduced waste, and increased process capability, which, in turn, strengthened its financial performance. We conclude the paper by discussing the limitations of the study (e.g. an application in a small business) and providing future research directions to further develop its underlying theory and validate the proposed TLS orientation construct by means of case studies and questionnaires. Some initial results are reported.