Tribal knowledge is any unwritten information that is not commonly known by others within a company. This term is used most when referencing information that may need to be known by others in order to produce quality product or service. The information may be key to quality performance but it may also be totally incorrect. Unlike similar forms of artisan intelligence, tribal knowledge can be converted into company property. It is often a good source of test factors during improvement efforts.
Example 1: A measurement system was out of control and the inspectors began fighting over what they believed to be the accurate gages. Gage R&R showed that 92% of the variation came from how the inspectors used the gage, not the gage itself.
Example 2: A product line was re-started after being down for two years but the original operators had to be re-hired in order to produce product that worked.