The Design and Engineering Methodology for Organisations (DEMO) method is a core method within the discipline of Enterprise Engineering (EE). It enables the creation of so-called essential models of organisations, which are enterprise models focusing on the organisational essence of an organisation, primarily in terms of the actor roles involved, and the business transactions between these actor roles. The DEMO method has a firm theoretical foundation. At the same time, there is an increasing uptake of DEMO in practice. With the increased uptake of DEMO also comes a growing need for enterprisegrade tool support. In this paper, we therefore report on a study concerning the selection, configuration, and extension, of an enterprise-grade tool platform to support the use of DEMO in practice. The selection process resulted in the selection of Sparx Enterprise Architect for further experimentation in terms of configuration towards DEMO. The configuration of this tool framework to support DEMO modelling, also provided feedback on the consistency and completeness of the DEMO Specification Language (DEMOSL), the specification language that accompanies the DEMO method.