Six Sigma: too slow for today’s high-speed race?

With so much at stake, Six Sigma's approach might not be the right fit for manufacturers looking for fast returns, argues a leading business change facilitator.

He says “ For a number of years, I have tried to be diplomatic when managers asked my advice about competing improvement programmes. Lean and Six Sigma have different strengths, I would say. Using kaizen teams, lean is fast and direct, creating immediate improvements and momentum toward one-piece flow. Six Sigma is analytical and narrowly focused, capable of rooting out hidden abnormality.”.

Many companies have been using both programmes side-by-side, creating scenarios in which black belts and "kaizen warriors" fight for resources and attention. The struggle and confusion that ensues has proved time and again that the two methodologies should not be implemented as separate but equal; one programme must take the helm. But which one?

Six Sigma has great tools, but as a programme it is too slow and narrowly focused to drive the kind of transformation most companies seek. Especially when compared to the speed and momentum of lean transformations, Six Sigma is a tortoise in a hare's world.

“Over the past few years”, he says “I have seen many disappointed managers - sold on a Six Sigma training programme at big upfront expense - that I cannot recommend the average Six Sigma programme at all.”

Six Sigma programmes can vary from one company to the next, but commonly they begin with a lot of upfront training of black belts, green belts and master black belts. Then black belts are often expected to pick their projects and forge ahead too often with limited oversight. Considering that most Six Sigma projects last six to nine months or more, the improvement work of an organisation can be off-track for months before it is apparent.

Most organisations that invest in improvement programmes are really seeking fast, dramatic change to improve productivity and quality. These are life and death issues in a business.

A lean kaizen team immediately attacks the wasted time inherent in a batch operation and realises productivity gains, often correcting quality issues while linking operations into one-piece flow. When Six Sigma is employed on operations that are still in batch mode, projects usually focus solely on the defect without taking into consideration additional factors. So black belts will often focus narrowly on projects such as material damage, for instance, without correcting the most basic cause, which is that batch operations force products to travel unnecessary distances in a plant, causing damage.

Some of you who have been aware of the Lean versus Six Sigma battles might see this article as the cross-border skirmishing from a Lean practitioner. This is not true. The statistical analysis tools in Six Sigma, as a means to pinpoint and eliminate abnormality, have been used to great effect for decades and should be included in any improvement initiative.

We have struggled through this issue of competing programmes at a number of organisations and realised that the toolsets of both programs were relevant and useful. It became quickly apparent though that, to effect real change, Lean needed to be in the lead, which is why the programme is called Lean Sigma.

The bias for action of a Lean program should lead improvement efforts so that the most common Six Sigma problem, which we all know as analysis paralysis, is not allowed to take root. Also, most companies need to start with basic Lean improvements before they can effectively leverage the power of Six Sigma variability reduction. At the same time, the analytical focus and excellent follow-up tools of Six Sigma should be integral to the programme to ensure that project improvements are sustained.

In companies that have implemented both Lean and Six Sigma, we now suggest a redefinition of the black belt role. Black belts should be team leaders or sub team leaders, getting out on the floor and guiding kaizen teams to generate fast, dramatic improvement, and then using their training in auditing and follow up to define the appropriate tracking metrics and seeing that it gets done. Black belts cross-trained in Lean will have the full complement of tools to select from, both during and after the event.

Like a good marriage, both Lean and Six Sigma are individually stronger for the active presence of the other. Six Sigma programmes alone, however, travel at a pace too unhurried for today's competitive landscape.