Originally published in the International Journal of Software Engineering and Knowledge Engineering, Feb 2000.

Business modelling methods are popular but, since they operate primarily in the early stages of software lifecycles, most are informal. This paper describes how we have used a conventional formal notation (first order predicate logic) in combination with automated support tools to replicate the key components of an established, informal, business modelling method: IBM's Business System Development Method (BSDM). We describe the knowledge which we represent formally at each stage in the method and explain how the move from informal to formal representation allows us to provide guidance and consistency checking during the development lifecycle of the model. It also allows us to extend the original method to a model execution phase which is not described in the original informal method. The role of the formal notation in this case is not to provide a formal semantics for BSDM but to provide a framework for sharing the information supplied at different modelling stages and which we can supplement with simple forms of automated analysis.