Organisational rules and regulations are vital components of a business. However, their growing numbers, interdependencies, and often unpredictable interactions with social agents make them challenging to manage. Enterprise modelling has proven an effective technique for sensemaking and creating a shared understanding of organisational structures, such as rules and goals. However, what is captured or not in a model depends on the theory used to examine the organisation, whether implicit or explicit. Particularly in healthcare, many scholars view organisations from the lens of Complex Adaptive Systems (CAS), rather than General Systems Theory (GST). This paper discusses how enterprise modelling of organisational rules grounded in CAS theory will have a different focus than if grounded in GST. Four key themes for are identified: abstraction, rule-agent interaction, emergence, and feedback channels. Each is discussed in light of privacy regulation and healthcare practice, and proposals are made for future research directions in enterprise modelling.