Is the tester functioning correctly?
• This should be a frequent test, and it should be easy enough that any operator can perform it. • Typically it involves testing a known good unit at the start of every shift. • Use tight limits that apply only to the known good unit, not just the regular test limits used for products. • Automate the software to look for drift and scatter in the test measurements. • For example: • Include a feature in the tester software to test many known good units. The software logs the test results and the serial number for each known good unit. • At the start of each shift, an operator performs the known good unit test. The software keeps track of how often the known good unit test is performed. If it is not performed, then the software will display a warning to the operator and not all testing to continue until the test is performed or an engineer has reset the warning. • The software compares each day’s known good unit test results against previous results for that same known good unit. When the
