More and more products got a shorter cycle of lifetime. Therefore the need for an flexible production and a short time to market cycle is important. Due to quality control, it is usual in most companies to do an final test with an in-circuit-tester (ICT). During this test of the completely assembled electronic product, the circuit can be freely connected and allows to do more than just testing. Our company has developed an In-Circuit-Serial-Programmer with a special adaptation for PIC microcontrollers from Microchip. The optimized power stages of these programmer are prepared to drive the pins of nearly every circuit. All necessary programming parameters are checked during programming. Different voltages for verification can be configured by the customer. Programming on an ICT saves money for an external programming service, which in addition possibly distort pins or lets some devices unprogrammed. An ICT with an inte-grated programmer allows a fast and flexible update of the target code and allows an individual program-ming of serial numbers and date stamps. Programming an individual calibration table of an assembled sensor, which was measured and calculated by a previous measurement loop, is an advantage too.