Lean Six Sigma

Lean Six Sigma is a process improvement approach that uses a collaborative team effort to improve performance by systematically removing operational waste and reducing process variation. It combines the many tools and techniques that form the "tool box" of Lean Management and Six Sigma to increase the velocity of value creation in business processes.
Lean Six Sigma's predecessor, Six Sigma, originated from the Motorola company in the United States in 1986. Six Sigma was developed within Motorola to compete with the kaizen (or lean manufacturing) business model in Japan.
In the 1990s, Allied Signal hired Larry Bossidy and introduced Six Sigma in heavy manufacturing. A few years later, General Electric's Jack Welch consulted Bossidy and implemented Six Sigma at the conglomerate.
During the 2000s, Lean Six Sigma forked from Six Sigma and became its own unique process. While Lean Six Sigma developed as a specific process of Six Sigma, it also incorporates ideas from lean manufacturing, which was developed as a part of the Toyota Production System in the 1950s.
The first concept of Lean Six Sigma was created in Chuck Mills, Barbara Wheat, and Mike Carnell's 2001 book, Leaning into Six Sigma: The Path to Integration of Lean Enterprise and Six Sigma. It was developed as a guide for managers of manufacturing plants on how to combine lean manufacturing and Six Sigma to improve quality and cycle time in the plant.
In the early 2000s Six Sigma principles expanded into other sectors of the economy, such as healthcare, finance, and supply chains.
Lean Six Sigma is a synergized managerial concept of Lean and Six Sigma. Lean traditionally focuses on eliminating the eight kinds of waste ("muda"), and Six Sigma focuses on improving process output quality by identifying and removing the causes of defects (errors) and minimizing variability in (manufacturing and business) processes.
Lean Six Sigma is based on the premise that in order to deliver service and product excellence, firms must not only have an in-depth knowledge of their internal processes, but also have a profound understanding of customers' current expectations and future needs.
Lean Six Sigma uses the Define, Measure, Analyze, Improve and Control (DMAIC) phases similar to that of Six Sigma. The five phases used in Lean Six Sigma aim to identify the root cause of inefficiencies and work with any process, product, or service that has a large amount of data or measurable characteristics available.
The different levels of certifications are divided into belt colors. The highest level of certification is a black belt, signifying a deep knowledge of Lean Six Sigma principles. Below the black belt are the green and yellow belts. For each of these belts, level skill sets are available that describe which of the overall Lean Six Sigma tools are expected to be part of a certain belt level. The skill sets reflect elements from Six Sigma, Lean and other process improvement methods like the theory of constraints and total productive maintenance. In order to achieve any of the certification levels, a proctored exam must be passed that asks questions about Lean Six Sigma and its applications.
Waste (muda) is defined by Fujio Cho as "anything other than the minimum amount of equipment, materials, parts, space, and workers time, which are absolutely essential to add value to the product".
Different types of waste have been defined in the form of a mnemonic of "downtime":