The holistic modelling of enterprise systems requires integrated views of both the technical systems as well as the organisational systems that together will provide the capabilities required. To survive in a competitive market, enterprises need to adapt to their environment and plan for incremental improvement of existing systems whether it be from minor upgrades through to the introduction of new disruptive technologies. Organisations are also extant in nature and exhibit characteristics of evolving, complex adaptive systems such as adaptability, self-organisation and emergence. Managing the complexity of this organisation in flux alongside the concurrent lifecycles of multiple technical systems of interest is not a simple task. A major factor causing this difficulty is how to express the "soft", human aspects of the organisation where measures can seem intangible, behaviour unpredictable or constrained to ad-hoc, qualitative assessment. In particular, although most businesses will have a view on organisational culture, how can these cultures be modelled in a manner that enables it to be integrated with the holistic enterprise system model in order to drive and yield useful and insightful assessments for practitioners? The authors have been developing integrated enterprise models that provide a variety of viewpoints and analyses into the impact of technology introduction on the evolution of organisational systems in Australian Heavy Rail systems. This paper describes a Model-Based Systems Engineering (MBSE) approach to the development of models of organisational culture within the context of an enterprise system and demonstrates how changes made to the integrated enterprise model may yield insight into how organisational culture will evolve as enterprise systems transform.