Abstract: A method and apparatus for monitoring and controlling a plurality of power supplies in a computer or similar complex electronic apparatus provides the steps of normalizing each power supply output according to a common nominal val ue, comparing the normalized values to a reference having values according to the normalized upper and lower limits specified for each power supply, and conducting a quantative measurement of out-of-tolerance test values. The specific upper and lower tolerance values for each normalized output are stored in digital form and the measurement of an out-of-tolerance reading is by comparison to a digital ramp extending only from the specific maximum or minimum tolerance threshold which is exceeded. The testing of plural power supplies having the same upper or lower normalized tolerance can be conducted as a group of tests against the same reference.