Abstract: The present invention relates to process development systems and related methods, including a process development wsystem comprising: a performance improvement rule generation module for generating a performance improvement rule set for at least one process factor from a generated rule set for the at least one process factor, each rule including a plurality of decision points corresponding to split variables relating to process conditions and a plurality of outcomes, wherein the performance improvement rule generation module is configured, for each rule from the or each generated rule set, to attach an activity flag at each decision point and thereby generate a performance improvement rule, the activity flag having one of two values indicative of whether the respective split variable is alterable or non-alterable by a process operator such as to enable operation of the performance improvement rule in determining which of the outcomes is attainable for given process conditions.