2.2 Lean

J. Womack, D. Jones, and D. Roos introduced the world to Lean thinking with The Machine That Changed the World [4]. They defined the principles of Lean production to include

• Teamwork;

• Communication;

• Efficient use of resources and elimination of waste;

• Continuous improvement.

Womack and Jones [5] expand on these principles to emphasize the Lean focus on waste:

• Specify value.

• Identify the value stream.

• Focus on flow of work.

• Implement customer pull.

• Strive for perfection.

These principles align very nicely with TOC by simply aligning value with the company goal. They also align with Six Sigma, but they put more emphasis on the system by focusing on the value stream and emphasize the ideas of customer pull and flow in a way that differs from Six Sigma. The U.S. Navy has defined their synthesis of Lean and Six Sigma as Lean Sigma.

Lean approaches have been finding their way into the world of project management with a delay similar to that experienced by TOC, perhaps in part for one of the same reasons: categorizing Lean as a production approach versus a project- management approach.

W. Dettmer [6] provides an excellent comparison and contrast of TOC and Lean approaches, concluding, TOC provides a useful system-level framework for directing lean thinking efforts where they will do the most good (the system constraint) and avoiding the pitfalls of applying them where they will do harm.

Dettmer also identifies some significant advantages to synthesizing Lean and TOC, including the following Lean...