Lean Six Sigma

Lean Six Sigma is a data-driven approach to improving efficiency, customer satisfaction and profits. 

Lean Six Sigma combines Toyota's lean manufacturing philosophy with the qualitative and quantitative techniques for driving process improvement that Motorola's Six Sigma management strategy provides.

Lean Six Sigma recognizes the role that stakeholders play in every project's success, as well as the importance of gathering and analyzing data to help those stakeholders understand the effectiveness -- or ineffectiveness -- of the workflow. The approach is pragmatic; it allows an organization to pick which parts of each discipline will help the organization meet its goals. 

How it fused with lean concepts

In order to understand the flexibility that Lean Six Sigma provides, it's important to understand a little about the similarities and differences between the two disciplines. 

Both lean management and Six Sigma seek to eliminate waste and improve business processes. An important difference, however, is that lean management relies on people to identify what problems are causing waste.

The philosophy of lean management is to do more with less, and it is built around two important principles: continuous improvement (kaizen) and respect for people.

All employees are expected to help eliminate waste; they receive just-in-time (JIT) training on a regular basis, and the tools they are given to identify and eliminate waste are designed to be easily understood and implemented. Lean management tools for process improvement include the 5 whyskanban inventory control cues, heijunka boxes for scheduling, Ishikawa fishbone diagrams, takt time calculations and value stream mapping.

Lean methods in healthcare

A hospital CIO explains how lean methods help health IT systems

Six Sigma, on the other hand, relies on data to identify problems in a business process. The management philosophy was named after the Greek letter sigma, which is used in statistics to denote variation from a standard.

In order for a company to achieve Six Sigma, it cannot produce more than 3.4 defects per one million opportunities for nonconformance. Its tools are designed to be used by a select number of employees who have been chosen to receive formal training in progressive levels of study.

Six Sigma project management tools include statistical analysis, stochastic optimization and engineering process control. Management strategies include DMAIC (define, measure, analyze, improve, control) and DMADV (define, measure, analyze, design, verify), both of which are based on Deming's plan-do-check-act cycle.

What is Lean Six Sigma used for?

As is mentioned above, Lean Six Sigma methodology is the combination of the lean manufacturing ideology popularized by Toyota and Motorola's six sigma strategy. This combination makes Lean Six Sigma an effective tool to optimize business processes and customer relations and, in turn, to improve profits.

Toyota's manufacturing process has, since shortly after World War II, prioritized minimizing bloat and maximizing flexibility. Hand in hand with this Toyota-inspired ideology is the Six Sigma management strategy, the brainchild of a Motorola engineer in the 1980s.

Where lean manufacturing emphasizes streamlining business processes, Six Sigma focuses on eliminating defects in these processes. Six Sigma teams seek to eliminate defects in business processes by minimizing variation in the processes.

Lean Six Sigma is often associated with the Xerox Corporation. In the early part of this century, the company implemented Lean Six Sigma to improve customer experience (CX) and to become more cost competitive. Since then, Xerox has promoted how it has successfully combined the infrastructure of Six Sigma with the philosophy of continuous improvement from lean manufacturing to streamline the company's internal processes and provide customers with quality products and services at speeds and prices that customers value. One of those services happens to be helping Xerox customers use Lean Six Sigma to improve their own business processes.

Certifications and training

Lean Six Sigma certification can be attained at varying levels based on the training an individual has received. Lean Six Sigma certification levels are divided into belts similar to the levels used in martial arts training.

The first level of Lean Six Sigma certification is the Six Sigma white belt. The white belt aims to provide trainees with a fundamental understanding of Lean Six Sigma methodology, including but not limited to process improvement, variability, eliminating negative effects on process performance and deciding what roles specific team members should play.

Next in the Lean Six Sigma certification ladder is the yellow belt. The yellow belt builds off of the training from the white belt certification course and aims to give trainees a more detailed and comprehensive understanding of Lean Six Sigma methodologies.

Following the yellow belt is the third step in the Lean Six Sigma training process, the green belt. The green belt focuses on the application of the Lean Six Sigma methodologies outlined in the white and yellow belt courses. In green belt training courses, trainees learn to chart and plan the roles of individuals within Lean Six Sigma teams, in addition to learning how to run statistical tests that are used to improve processes.

The final belt that is given out in the Lean Six Sigma certification process is the black belt. The Lean Six Sigma black belt teaches trainees to explain multiple regression, perform factorial experiments, determine size calculations for experiments and describe different types of process optimization. In short, the black belt is the pinnacle of Lean Six Sigma training.

This was last updated in May 2018

Continue Reading About Lean Six Sigma

Dig Deeper on IT project management and portfolio management