Monday 24 August 2009

Lean Versus Six Sigma


Six Sigma is problem focused with a view that process variation is waste. Lean Thinking, on the other hand, is focused on process flow and views any activity that does not add value as waste. Six sigma uses statistics to understand variation. Lean uses visuals: process mapping, flowcharting, and value stream mapping, to understand the process flow.


Taiichi Ohno is credited with creating the Toyota Production System (TPS), which is one of the better known implementations of Lean Thinking anywhere in the world. The concepts of lean were born out of the severe resource constraints in postwar Japan, which leads us to next week’s process improvement program - Theory of Constraints.

Lean Thinking is ideal for mature (energy), slow growth (automotive), low transaction industries (small business) or an organization where mathematical tools are not common. Lean begins to use systems thinking and considers all of the process interactions.

But lean is still a reductionist approach focused on eliminating waste (cutting costs). What is needed is to balance the resources released through Lean or Six Sigma improvement programs with an increase in throughput and need for resources. Otherwise you enter a cost cutting, job losing cycle and your process improvement program will grind to a halt.

If you are in a mature, slow growth, low transaction, or non-math business then Lean Thinking will work real well for your organization.
So what’s left? Six Sigma and Lean use two different approaches to get the same end result – process improvement. The Theory of Constraints (throughput improvement) takes the concepts of Lean Thinking to another level of systems thinking.

1 comment:

Anonymous said...

Trying to contrast lean and six sigma may be helpful to point on some characteristics of each. But such attempts often distort the approaches too much to be useful. Lean is not good for old, slow companies. Lean is the name given Toyota's practices. Those practices were developed from Henry Ford and Dr. Deming's ideas when Toyota was just deciding to manufacture cars. Lean thinking continues to grow and evolve. If lean is being done in some way that inhibits rapid reaction it is being done very poorly. Lean is a great strategy for many and has a huge following in software development. Some related blog posts:

http://management.curiouscatblog.net/2007/08/21/improvement-tools-and-improving-management/

http://management.curiouscatblog.net/2007/05/03/toyota-lean-consultants/

http://management.curiouscatblog.net/2006/05/30/lean-software-development/

http://management.curiouscatblog.net/2006/09/10/going-lean-brings-long-term-payoffs/