During the development of processes for high production CHO fed batch cultures, there is usually insufficient time for thorough process optimization. Once defined, these processes often have ranges rather than specific values for many parameters, resulting in minor variations in the runs. These small process variations, combined with resultant differences in performance, can be used to further optimize the process. Over the course of one year, eleven 20 L fed batch cultures of an antibody producing CHO-S cell line were generated in the Allegro XRS 20 bioreactor. In addition to normal minor process variation, small process changes occurred due to method optimization efforts or culture timing requirements. An analysis of the combined historical data was undertaken to better understand the specific culture performance drivers, leading to further improvement in culture outputs, specifically final antibody concentration and maximum viable cell density (VCD).