Six Sigma vs Lean: some perspectives from leading academics and practitioners

The purpose of this paper is to present the fundamental and critical differences between two of the most powerful methodologies in a process excellence initiative in any organisation. The approach taken was to collate opinions from a number of leading academics and practitioners from five different countries. It was also important to ensure that all participants have a good knowledge and expertise in the field of both Lean and Six Sigma methodologies. Although both methodologies are focused on process and quality improvement, Lean is formalisation and codification of experience and judgement which is not a feature of Six Sigma. Lean emphasises speed and waste, however Six Sigma emphasises variation, defects and process evaluation. The viewpoints expressed in the article are those of a few academics and practitioners. It is important to capture the viewpoints of more academics and practitioners to arrive at sound and valid conclusions. The paper provides an excellent resource for many researchers and for practitioners who are engaged in research and applications of the most two powerful methodologies for achieving and sustaining operational excellence. It is also critical to understand the fundamental differences between these two methodologies.