SOP is a major element of the product life-cycle, and a key milestone of the
APQP process, by closing the
"Product and Process Validation" phase, and starting the serial life of the part.
From the start of production all parts are produced under serial conditions, but these are not the first ones produced that way. In the automotive sector, the
PPAP (or 0-series) parts are already produced under serial conditions. To start a reliable serial production, variation and risk must be minimized.
To reach this goal, the automotive specific APQP framework has been elaborated by the big three American carmakers. According to the APQP process, the following key elements / points / inputs must be closed to
start the serial production: