Structural Process Variety and Standardization

Structural process variety occurs due to control-flow differences among alternative process execution variants, i.e., trace variants. Structural variety is an important indicator for analyzing process performance, identifying process changes, guiding process model discovery, or sampling process data. Yet, existing measures in the research literature do not capture structural process variety in a consistent and mathematically sound way. In this paper, we identify a property called ultrametric, which ensures that a measure, based on the pairwise comparison of trace variants, leads to a meaningful and unique structural variety value. Thereupon, we propose a measurement framework, that guarantees the ultrametric property and provides a ranking of trace variants within a set of multiple trace variants, according to their contribution to the set’s overall structural variety. One important implication of our work is, that our framework can be applied to substantially improve process standardization efforts.