How Six Sigma drifted into programme thinking, and how it affected Lean

The Six Sigma Wave – perfectly distributed

By the mid-1990s, the improvement world had found a new hero.
Lean and TOC found themselves in the shadow of the new contender on the improvement scene: Six Sigma was here.  Six Sigma, born at Motorola and made famous by Jack Welch at GE was taking the 90s by storm.  And all this based on standard deviation and statistics!  I mean, you have to hand it to the team; making stats cool is not an easy thing.

I was in a UK automotive company when one of the first Six Sigma programmes was being rolled out.  As a Lean consultant I was worried as my internal team were being reassigned to Black Belt training. This was a scientific method to eliminate variation and defects through statistical discipline taking hold, and to a degree, I could see why.  

Origins and Intent – What Six Sigma Actually Solved

Six Sigma began as a focused engineering approach.  Motorola engineers Bill Smith and Mikel Harry were hell-bent on eliminating variations in semiconductor manufacturing. Their goal was simple: reduce variation, reduce defects, increase reliability.  This was about ‘design for manufacturability’.  And for that, I salute these gentlemen.  The Baldrige Award was well deserved.  I’ve heard talk of Motorola’s later misfortunes being associated with the Six Sigma deployment, which is unfortunate.  Their weakness was not Six Sigma but a seismic shift in smartphone technology.

The shift

At Motorola, Six Sigma worked precisely because it lived within an operational context that already had stability and capable processes.  At GE, it became a movement.

Jack Welch expanded Six Sigma from a quality improvement method into a company-wide performance programme at GE. Advancement and recognition increasingly became linked to certified project outcomes, which elevated the role of Six Sigma specialists within the organisation.

Over time, this contributed to a shift in where improvement expertise was perceived to reside with the belt structure  rather than in day-to-day operational teams.

How Black Belts Changed the Game, And the Culture

In early 2003 I was asked to help an international company quietly restructure its Six Sigma programme as things were getting feisty on the shop floor.  I say quietly, as they had declared the programme publicly and had no way of undoing the statement.  Shareholders were hungry for results.  

What I discovered, was a significant morphing in the original intent of Six Sigma.  The Motorola boys must have been smarting.  This was no longer about defect elimination through process control.  When I sat with two of the Master Black Belts, both very smart, they took me through the hopper of Black Belt projects and to my astonishment, the top twenty were looking for headcount reduction.  Headcount was considered a Type 1, or Hard saving.  It was immediate to the bottom line.  The MBBs and BBs were hunting people.  They were the ‘Predators’ of Schwarzeneggar’s famous film and had been christened such by the production team leaders.  Managing variation and the hunt for defects was considered passé.    The gemba was, in some cases,  a hunting ground where operators sought refuge behind CNC machines (I kid you not).

I couldn’t have a discussion about levelling and inventory reduction as a way of exposing waste.  This just wasn’t fast or furious enough.  Sorry, no more film analogies. 

By the time I left, the international was still trying to win back the trust of the floor.  The Black Belts were still there but felt cheated from a pathway to promotion as the exec team curbed the savings approach.  The team leaders spurned DMAIC and Green Belt training as it was considered a betrayal of the floor.   The operators steadfastly refused to participate in any improvement activity, and the unions had a field day. This was going to be a long road to recovery.

As I moved through further engagements, the performance emphasis, rather than the original intent of defect reduction, was fast becoming the norm.

Reducing Toyota Systems 

The Lean Six Sigma movement, in my view, made it harder still to build a lasting culture of continuous improvement.   Whilst we may think we are doing our clients a favour by packaging up a performance programme with a philosophical production system, we simply reduce Toyota systems to mere ‘tools’ in the toolbox, there to be used as and when needed, rather than applied holistically as part of a principle-based system. Standardised Work, One Point Lessons, Error Proofing, 5S… all now ‘independents’ in the improvement toolbox without a north star.

My other observation was the disenfranchisement of the team leaders as the hybrid approach took hold.  The voice of the operation was being lost to the select few. And as the distrust grew between the belts and the floor, the shop floor leaders disengaged.

Lessons and Reflections

Six Sigma’s mathematical discipline brought rigour.  I have to say I love the elegance of the maths, and see its merit.  But with the maths came a distancing from the shop floor. 

Toyota achieved similar process capability without elevating statistics to an ideology, but more importantly for Lean enthusiasts, they doubled down on Kaizen.  The fruits of improvement continued being delivered from the many and not the few.  Team Leaders held the key to changes, small, numerous and impactful on waste, whilst the Jidoka pillar continued to expose defects for elimination.

• Where Six Sigma rewarded projects, Toyota rewarded learning and engagement
• DMAIC elevated improvement to the higher echelons, whereas PDCA kept it grounded in the teams.
• Where performance-based Six Sigma brought distrust to the floor, waste elimination continued at pace.
• Toyota’s genius lies not in standard deviation, but in standard work.
• Programmes fix problems; systems build capability. 

Still love the maths, though.