A rational reconstruction of Six‐Sigma's breakthrough cookbook

Purpose – The purpose of this paper is to develop a consistent and crystallized exposition of Six‐Sigma's methodology for improvement projects, which could serve as a basis for subsequent scientific research of the method. Design/methodology/approach – The paper shows that reformulation of imprecise and unscientific formulations of knowledge is called rational reconstruction. Starting from accounts given in the Six‐Sigma literature, a descriptive reconstruction of the main elements of the Six‐Sigma method is made: its business context, strategy, tools and techniques, and concepts and classifications. Findings – The paper finds that, although, on the face of it, it may seem that accounts given in literature diverge, analysis shows that variations are superficial rather than essential. The analyses result in precisely formulated accounts of Six‐Sigma's method (DMAIC phases, steps, and tools), its business context, and its terminology. Essential anomalies are discussed. Six‐Sigma's claims of being data‐driven and focused on customers and bottom line results appear to be substantiated by its method. Research limitations/implications – In this paper the presented reconstruction has a purely descriptive impetus: it structures accounts that the Six‐Sigma literature itself provides, without critical evaluation against theoretical frameworks beyond the Six‐Sigma literature. As such, it provides a basis that is suitable for subsequent scientific research. Practical implications – The paper sees that loose and inaccurate expositions of Six‐Sigma's project methodology are supplemented with a precise formulation. Originality/value – Among a tide of accounts of Six‐Sigma's DMAIC method, this paper provides an account that meets scientific standards of precision and consistency. It allows a substantiation of commonly made claims about Six‐Sigma, i.e. Six‐Sigma is a quantitative, data‐driven approach focused on cause‐and‐effect relations, and offering new solutions instead of standard cures.