Graphical models are used to depict relevant aspects of real-world domains intended to be supported by an information system. Various approaches for modeling exist and approaches such as object-oriented and process-oriented modeling methods are in widespread use. These modeling methods differ in their expressive power as well as in their complexity of use, thereby leading to an important investment decision for organizations seeking to conduct modeling projects. In this paper, we used an established approach for evaluating the complexity of conceptual modeling methods and compared two important industry standards for modeling, Unified Modeling Language and Business Process Modeling Notation, based on their complexity. Our research finds that BPMN has very high levels of complexity when contrasted with UML.
Recker, Jan; Muehlen, Michael zur; Siau, Keng; Erickson, John; and Indulska, Marta, "Measuring Method Complexity: UML versus BPMN" (2009). AMCIS 2009 Proceedings. 541.