Joint Polar Satellite System (JPSS) data product improvement requires a substantial record of on-orbit data extending over years. Such a data record now exists for the JPSS instruments developed for the Suomi National Polar Orbiting Partnership (SNPP) risk reduction mission. SNPP has now provided well over three years of on-orbit data from four JPSS instruments and derived data products. It is now feasible to apply a system engineering approach to data product improvement. In this approach on-orbit performance characteristics are traced back to instrument and algorithm design characteristics and pre-launch test data. During the instrument development phase system engineering was applied in the reverse direction, to trade off and optimize designs to meet requirements based on predicted performance. The key to data product improvement is comparison of on-orbit performance with performance predicted prelaunch and feedback of comparison findings into the design and development process for future JPSS instruments and algorithms.