Lean & Six Sigma

By Al Norval

I deal with several organizations where the competition between Lean and Six Sigma is nothing short of destructive for the organization. These typically large organizations have two camps both of whom are dug in and set in their ways. They seem to spend more time fighting with each other than actually helping people in the organization make improvements. The skirmishes typically involve sending articles around the organization by email where the pundit has an opinion that supports one side or the other.

I’m always puzzled by this as both improvement methodologies are necessary. Some organizations understand this but end up splitting the two improvement methodologies anyway with statements like “Lean is about removing waste and Six Sigma is about reducing variation”

Hogwash. While reducing Muda (waste) is a key pillar of Lean, so is reducing Muri (Strain) and Mura (variation). These three concepts are related as Strain and Variation are causes of Waste. Strain or Overburden applies both to machines and manpower. We can see it when equipment is made to run faster than it’s capable of or IT systems become overloaded with new software. When it’s applied to people it lines up with another pillar of Lean – Respect for People. Strain here often leads to ergonomic issues. Asking people to do work that causes injuries certainly isn’t showing them due respect.

Likewise Six Sigma is about reducing variation but more importantly it’s about making data driven process improvements using DMAIC which is a variant of Deming’s PDCA cycle.

In both cases, organizations have good people working in broken processes.

The trick is to apply the right technique to the right problem. Here’s my recommendation:

When problems require simple problem solving, use Lean. When faced with complex problems use Six Sigma.

Abraham Maslow once said “If the only tool you have is a hammer, it’s tempting to treat everything as a nail”

In my opinion, both improvement methodologies are necessary. Learn to coexist and get on with the real work of helping people make improvements enabling the organization to achieve its goals.

Cheers