Page 236 - The Handbook for Quality Management a Complete Guide to Operational Excellence

222 P r o c e s s C o n t r o l Q u a l i t y A u d i t s 223

• Product characteristics to be monitored and how they will be
monitored
• Workmanship criteria
• Maintenance procedures
• Verification methods (process qualification)

Work instructions should be written in clear, simple terms, using the
language that is easiest for the person doing the work to understand. The
people doing the work should be intimately involved in preparing the work
instruc tions. Pictures, diagrams, graphics, and illustrations should be
used to make the documentation easy to understand and apply. If the
instructions are voluminous, they should include such aids as indexes,
tables of contents, tables of figures, tabs, etc. to assist in locating relevant
information. Of course, to ensure that they are up-to-date, the documenta-
tion should be cross-indexed to the engineering drawings, purchase
orders, or other documents that they implement. Work instructions should
be part of the overall document control system of a firm.

Classification of Characteristics
All but the most simple products or services include large numbers of
features or characteristics of interest to the customer. In theory, every fea-
ture of every unit produced, or every transaction conducted, could be
inspected and judged against the requirements. This would add consider-
able cost to the product and, for most features, add little or no value to the
customer. Instead, it is better to establish a hierarchy of importance for the
various characteristics of the product or service. Which features are so
important that they deserve a great deal of attention? Which need only a
moderate amount of attention? Which need only a cursory inspection or
review? The activity of arriving at this determination is known as classifi-
cation of characteristics.
In practice, characteristics are usually classified into the categories crit-
ical, major, and minor. The terms can be defined in simple terms as follows:

Critical characteristic. Any feature whose failure can reasonably be
expected to present a safety hazard either to the user of the product, or
to anyone depending on the product functioning properly. For service,
any characteristic that would lead to legal implications, or severely
impact reputation.
Major characteristic. Any feature, other than critical, whose failure
would likely result in a reduction of the usability of the product. For
service, any characteristic that would lead to loss of goodwill or future
business.

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