Page 354 - The Handbook for Quality Management a Complete Guide to Operational Excellence

340 C o n t i n u o u s I m p r o v e m e n t I m p r o v e / D e s i g n S t a g e 341

Figure 16.1 Example PDPC (Pyzdek and Keller, 2010).

There are three main categories of human errors: inadvertent errors,
technique errors, and willful errors.

Inadvertent Errors
Many human errors occur due to lack of attention. People are notorious
for their propensity to commit this type of error. Inadvertent errors have
certain hallmarks:

• There is usually no advance knowledge that an error is imminent.
• The incidence of error is relatively small. That is, the task is
normally performed without error.
• The occurrence of errors is random, in a statistical sense.
Examples of inadvertent errors are not hard to find. This is the type of
error we all make ourselves in everyday life when we find a mistake bal­
ancing the checkbook, miss a turn on a frequently traveled route, dial a
wrong number on the phone, or forget to pay a bill. At home these things
can be overlooked, but in business they can have significant costs and con­
tribute to wasted resources.
Preventing inadvertent errors may seem an impossible task. Indeed,
these errors are among the most difficult of all to eliminate. As the error
rate becomes small, the improvement effort becomes more difficult. Still,
in most cases it is possible to make substantial improvements economi­
cally. At times it is even possible to eliminate the errors completely.
One way of dealing with inadvertent errors is foolproofing, also
known as poka yoke. Foolproofing involves changing the design of a pro­
cess or product to make the commission of a particular human error

16_Pyzdek_Ch16_p335-348.indd 341 11/9/12 5:16 PM