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Six SigmA 113
including this element, practitioners are emphasising the need to improve whole pro-
cesses rather than individual elements of a process.

Process improvement
Some of the ideas of continuous improvement are also now formally included in Six
Sigma, but it does not confine itself to continuous improvement only. In fact, Six
Sigma projects may often be relatively wide in scope and aim to achieve relatively large
improvements.

Criticisms of Six Sigma

One common criticism of Six Sigma is that it does not offer anything that was not
available before the term was used. Its emphasis on improvement cycles comes from
TQM, its emphasis on reducing variability comes from statistical process control,
its use of experimentation and data analysis is simply good quantitative analysis.
The only contribution that Six Sigma has made, argue its critics, is using the rather
gimmicky martial arts analogy of Black Belt, and so on, to indicate a level of exper-
tise in Six Sigma methods. All Six Sigma has done is package pre-existing elements
together in order for consultants to be able to sell it to gullible chief executives. In
fact, it’s difficult to deny some of these points. Maybe the real issue is whether it
is really a criticism. If bringing these elements together really does form an effec-
tive problem-solving approach, why is this a problem? Six Sigma is also accused of
being too hierarchical in the way it structures its various levels of involvement in the
improvement activity (as well as the dubious use of martial arts-derived names such
as Black Belt). It is also expensive. Devoting such large amounts of training and time
to improvement is a significant investment, especially for small companies. Neverthe-
less, Six Sigma proponents argue that the improvement activity is generally neglected
in most operations and, if it is to be taken seriously, it deserves the significant invest-
ment implied by the Six Sigma approach. Furthermore, they argue, if operated well,
Six Sigma improvement projects run by experienced practitioners can save far more
than they cost.
There are also technical criticisms of Six Sigma, most notably that in purely sta-
tistical terms the normal distribution that is used extensively in Six Sigma analysis
does not actually represent most process behaviour. Other technical criticisms (that
are not really the subject of this book) imply that aiming for the very low levels of
defects per million opportunities, as recommended by Six Sigma proponents, is far
too onerous.

lessons from Six Sigma

If one were cynical one would argue that the real lesson from Six Sigma is that with a
scientific-sounding title and a set of common sense analytical tools, consultants can
sell anything. But whether one accepts that or not, one cannot deny the success of how
Six Sigma has been sold. So, maybe a more charitable view is that there is a genuine
hunger for, and appreciation of, evidence-based improvement tools. Certainly, one can
argue that before Six Sigma there was too little emphasis on evidence-based and statisti-
cal analysis. Softer and more cultural and behaviour-based approaches are useful, but
they must be balanced with more rigorous quantitative perspectives.

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