You may have encountered various terms associated with Lean philosophy, such as Six Sigma, different belt levels, and industry-specific Six Sigma variations. But what do these terms actually mean?

Six Sigma is a methodology focused on controlling business processes by minimizing defects and enhancing quality. It operates on the principle that defects arise from deviations, and thus, the goal is to maintain no more than six sigma (standard deviations) between a process and its norm. Six Sigma involves understanding customer needs, analysing data, and improving processes. The different belt levels—yellow, green, or black—indicate varying degrees of expertise in Six Sigma practices.

Lean, on the other hand, encompasses a set of tools aimed at enhancing workflow and reducing waste in business processes or material production. These tools can be applied independently or as part of a Six Sigma initiative.

Lean Six Sigma is a hybrid approach that integrates the two methodologies. It begins with Lean techniques to streamline processes, followed by the application of Six Sigma tools to minimize deviations and defects.

Design for Six Sigma (DSS) and Design for Lean Six Sigma (DLSS) are methodologies used to design (or re-design) products and processes from scratch using Six Sigma or a combination of Six Sigma and Lean tools. These methodologies focus on getting it right the first time rather than improving it later.

Although frequently used in manufacturing industries, it is worthwhile to note that Six Sigma and Lean have been customized and specialized for a wide variety of industries, including health care, agriculture, services, hospitality, education, and construction.