November 2001

Vol. 3, No. 11

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 ways:

  1. In planning and in guiding decisions along the journey;

  2. 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 useful.


  1. 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.

  2.  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.

  3.  A purpose that focuses only on short-term profit will eventually threaten the viability of the system.


  1. 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
  2. Everyone desires community. People are social animals. Systemic and organizational health improves when new connections are made and existing ones strengthened.

  3. 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 high creativity.

  4. The power of the status quo is very strong. The tension between organizational status quo and the changing world creates pain and fear.

  5. 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.

  6. 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.


  1. Everything is one of a kind. If things look alike, the measurement system is not sensitive enough.

  2. Reducing numerical variation toward perfection is a powerful way to improve performance.

  3. 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 choices.

  4. '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.

  5.  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.

  6. 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

  1. 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 organization.

  2. Many performance evaluations, merit and incentive pay, and promotion systems suboptimize organization performance.

  3. 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.


  1. 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.

  2. 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 Publishing, 1992).

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 think. You can reach me at

Copyright 2001 PQ Systems.

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