Current trends place increasing emphasis on enterprise modelling as an effective means of making BPR initiatives successful. Current modelling technology allows the use of enterprise models to go far beyond descriptive purposes; in fact, such models can play a major role in defining and managing business processes and in mapping business processes to support systems such as ERPs and workflow systems. This paper presents an operational extension to the CIMOSA methodology, which is based on the OPJ modelling formalism. OPJ is supported by the PrimeObjects modelling and simulation tool. This integrated approach can be used to perform checks on the enterprise model, to simulate business processes and to build prototypes of enterprise-wide software applications, such as workflow management systems. (C) 1999 Elsevier Science B.V. All rights reserved.