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Tuesday, February 16, 2010

Mistake Proofing Help

We all make mistakes, to err is human.  The questions are why does it happen and how can you prevent it.  Mistake-proofing is the use of process design features to facilitate correct actions, prevent simple errors, or mitigate the negative impact of errors Poka-yoke is Japanese slang for mistake-proofing, a term coined by Shigeo Shingo.

John Grout has researched mistake-proofing extensively for the past 17 years. John is dean of the Campbell School of Business at Berry College, Rome, Georgia, and the David C. Garrett Jr. Professor of Business Administration. In May 2007, John's book "Mistake-Proofing the Design of Healthcare Processes" was published by the Agency for Healthcare Research and Quality as a government document that is distributed free to the public and can be downloaded here (pdf). In 2004 John received the Shingo Prize for his paper, The Human Side of Mistake-Proofing with Douglas Stewart.

For resources on mistake proofing visit John Grout's Mistake-Proofing Center.  John's suggests, starting by looking at some everyday examples, then taking a look at the Brief Poka-Yoke Tutorial.  I would suggesting following this up with a review of bad designs, a scrapbook of illustrated examples of things that are hard to use because they do not follow human factors principles.

I think is particularly worthwhile highlighting this section from Grout's tutorial which originated from Shigeo Shingo who formalized poka-yoke:


The ability to find mistakes at a glance is essential because, as Shingo writes, "The causes of defects lie in worker errors, and defects are the results of neglecting those errors. It follows that mistakes will not turn into defects if worker errors are discovered and eliminated beforehand"[Shingo 1986, p.50]. He later continues that "Defects arise because errors are made; the two have a cause-and-effect relationship. ... Yet errors will not turn into defects if feedback and action take place at the error stage"[Shingo, 1986, p. 82].
According to Shingo [Shingo, 1986, p.71], "Defects will never be reduced if the workers involved do not modify operating methods when defects occur." The willingness to take corrective action is a function of the attitude and commitment of both managers and workers, not an intrinsic attribute of a particular approach to quality management.

You should also visit The Lean Enterprise Institute (LEI) to view Grout's healthcare webinar on mistake proofing to reduce medical errors (or view slides).

John suggests there is a new attitude to preventing errors requiring a new remedy:


"Think of an object's user as attempting to do a task, getting there by imperfect approximations. Don't think of the user as making errors; think of the actions as approximations of what is desired." Source: Norman, The design of everyday things. Doubleday 1988.

"The remedy is in changing systems of work. The remedy is in design." Donald Berwick hopes "that normal, human errors can be made irrelevant to outcome, continually found, and skillfully mitigated."

John Grout says you need to think about how to stop mistakes like your life depends on it because it just might. Get started today learning how you can stop mistakes with these great resources.

1 comment:

  1. The GBMP Poka-yoke Lean Training DVD is pretty good too - lots of shop floor examples of implemented poka-yokes and the employees who identified the problems and figured out the fixes. It's affirming for anyone struggling with Poka-yoke because viewers see that anyone can participate and (like the definition says) there's no expensive cost. It's really about capturing the creativity of your people. They have the answers. Let them show you.

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