What is “Lean”?

Lean Manufacturing describes production method based upon the Toyota Production System. The term “lean” was coined by John Krafcik in 1988 in his article, “Triumph of the Lean Production System,” and was explained by Jim Womack and Dan Jones in 1990 in, “The Machine That Changed the World” and later refined by the same authors in 1996, “Lean Thinking.”

Womack and Jones defined the five principles of lean as:

• Specify the value of the product or service from the customer’s viewpoint

• Identify the Value Stream for each product or service, and remove all non-value adding steps (muda, or waste)

• Make value flow smoothly without interruption

• Let the customer pull from the producer

• Pursue perfection through the continual improvement

In lean, work processes are designed (or continually improved) to remove the Seven Deadly Wastes, or muda:

• Transportation

• Inventory

• Motion

• Waiting

• Overproduction

• Overprocessing

• Defects

Lean Manufacturing principles have been extended to several other industries and applications. In addition to Manufacturing, lean is applied in services, construction, healthcare, education, government entities, and other areas. The guiding principles of lean can be extended to apply to any business or organization.

A Note About Other Continuous Improvement Approaches

Lean is related to and shares commonalities with other improvement systems, methodologies, philosophies and schools of thought, including Operational Excellence, Agile, Six Sigma, Lean Six Sigma, Theory of Constraints, the Toyota Production System, 80/20, and many, many others. While all share a common goal of Continuous Improvement, these approaches are often found “competing” simultaneously in the same organizations.