Purpose - The purpose of this paper is to explore the dynamics of critical thinking (CT) in contrast with Six Sigma and the "5 Whys" approach that is used by many managers to conduct "Root cause analysis" in business process improvements. Design/methodology/approach - The research integrates principles of traditional literature review with a reflective inquiry of a practitioner. Findings - Six Sigma and its "5 Whys" methodology is insufficient in root cause analysis unless coupled with CT. The paper demonstrates that some extraordinary business successes were achieved by CT, while catastrophic failures were often the result of selective biases, rigid thinking, and/or tendencies to deal with steps of processes, isolated processes, and/or independent situations. Consequently, the paper identifies a new domain that can be added to training in Six Sigma and 5 Whys. Research limitations/implications - The study does not address specific ways to integrate CT into Six Sigma, 5 Whys, and/or root cause analysis in business process improvement initiatives. Future research is needed in this area. Originality/value - The paper explores a new perspective to convalescing Six Sigma and 5 Whys methods. It provides a specific example and suggestions to help practitioners avoid faulty conclusions, while conducting investigations to improve business processes. It also opens the door for encompassing aspects of CT in Six Sigma training. As such, it benefits both practitioners and academics.
