Six Sigma and More:
Beliefs and assumptions
by David R. Schwinn
It may be useful to reflect on what our readers say
about Six Sigma in their own organizations. As with many other initiatives,
people's reactions are mixed. Readers tell me that in their organizations,
outcomes are different: 'outstanding results, ' 'stuck in our tracks, '
'nice to see consistent direction, ' and 'it's destructive to the
human side of our business. '
I jumped to a deeply held belief of mine. When a
change initiative lacks a shared theory or set of beliefs and assumptions,
the results are likely to be spotty or, perhaps, just poor. Rosabeth Moss
Kanter, in The Change Masters (New York: Simon & Schuster, Inc., 1983),
illustrates this point with a story:
'I call this the ‘Roast Pig' problem after
Charles Lamb's classic 1822 essay ‘A Dissertation on Roast Pig,' a
satirical account of how the art of roasting was discovered in a Chinese
village that did not cook its food. A mischievous child accidentally set
fire to a house with a pig inside, and the villagers poking around in the
embers discovered a new delicacy. This eventually led to a rash of house
fires. The moral of the story is: when you do not understand how the pig
gets cooked, you have to burn a whole house down every time you want a roast
pork dinner. '
My beliefs and assumptions about what is required for
a successful Six Sigma initiative follow. I think they may be useful in two
- In planning and in guiding decisions along
- As a touchstone to be used when progress
stalls. My experience is that roadblocks result not from difficult people
or technical problems. They come from deep-seated issues around purpose,
fundamental beliefs about people, lack of understanding of the behavior of
numbers, dysfunctional systems and structures, and lazy learning.
These beliefs and assumptions are like any other model
as described by Gerald Nadler and David Ralston in Integrative Problem
Solving (Morcross, Georgia: Industrial Engineering and Management Press,
1986), 'All models are wrong, but some are useful. ' I hope this one is
- There needs to be constancy of purpose,
which means everyone needs to be involved in the development of the
mission. People support what they create.
- At least part of the mission of any Six
Sigma initiative is to seek perfection and the elimination of defects,
while understanding that perfection or zero defects is impossible to
achieve. This is best done with a focus on the prevention of defects,
rather than the inspection and rejection of them.
- A purpose that focuses only on short-term
profit will eventually threaten the viability of the system.
- Everyone wants to make a unique, positive, meaningful contribution
and has the capability to do so. It is management's job to provide the
encouragement and support for everyone to make his or her contribution.
This support and encouragement includes:
- Clear expectations and instructions
- Workable tools, equipment, and facilities
- On-the-job training
- Access to broader education
- Everyone desires community. People are
social animals. Systemic and organizational health improves when new
connections are made and existing ones strengthened.
- Everyone leads and everyone follows. An
environment that encourages the natural, organic dance between these two
roles for all stakeholders leads simultaneously to high performance and
- The power of the status quo is very
strong. The tension between organizational status quo and the changing
world creates pain and fear.
- Pain and especially fear tend to drive
people into their 'fight or flight, ' reptilian brain. This situation
makes both logic and creative thought very difficult.
- Excessive employee and management
turnover, even if it is internal, can be destructive. People need adequate
time to learn their jobs. They also need enough time on the job to see
both the long- and short-term results of their actions.
- Everything is one of a kind. If things
look alike, the measurement system is not sensitive enough.
- Reducing numerical variation toward
perfection is a powerful way to improve performance.
- Qualitative diversity, on the other hand,
is a gift. Rich diversity provides different perspectives leading to
better understanding. It also leads to enhanced creativity and more
- 'The most important numbers are unknown
and unknowable. ' (Dr. W. Edwards Deming, Out of the Crisis, Cambridge,
MA: MIT Center for Advanced Engineering Study, 1982). Things like success,
contributions, and quality are not measurable. We can only measure
surrogates for these variables. We tend to measure those things that are
easy to measure and control, rather than those that are important.
- Acting from an understanding of common
versus special cause variation is a powerful way to manage using numbers.
Unfortunately, this kind of action rarely goes beyond the factory floor.
Stretch goals, numerical objectives and targets developed and used in the
absence of a knowledge of variation, frequently suboptimize performance.
- Artificial creation of numbers, ratings,
and rankings usually results in win-lose competition, ineffective
allocation of resources, and the arbitrary destruction of organizations,
departments, and individuals.
Systems and Structures
- Organizations are living systems in which
everyone has choice. They are made up of subsystems and are part of larger
systems. Each of these interrelated systems has purpose, outputs,
structure, and processes. Every transaction represents an opportunity to
attempt to perfectly serve a customer. Treating these systems as an
isolated pyramid of stacked up boxes stifles partnerships and steals the
potential brilliance, performance, creativity, and life from an
- Many performance evaluations, merit and
incentive pay, and promotion systems suboptimize organization performance.
- Some people in the organization are
beating the systems and performing well by breaking the rules. There is
much to be learned from their efforts.
- Sustained performance improvement requires
learning. Learning is enhanced by making mistakes. Learning requires both
action and reflection. Walter Shewhart's Plan-Do-Study-Act cycle is a
simple, yet powerful, way to facilitate learning.
- All living systems go through a series of
life cycles that include creation, normalization, and innovation.
Organizations and their subsystems may be at different stages. The best
approach to change depends on a system's stage of development (George
Land and Beth Jarmen, Break Point and Beyond, New York, NY, HarperCollins
I hope this provides a useful framework from which to
develop your own common set of beliefs and assumptions. You can then build
your Six Sigma effort on your own framework. As always, let me know what you
can reach me at firstname.lastname@example.org.