Function Modeling lies at the HEART of all good business systems analysis, business process modeling, BPM (Business Process Management) and BPR (Business Process Re-engineering).
The very first stage for effective business modeling is to identify and model WHAT the business OUGHT to be doing. The discrete activities that a business does are called Business Functions or, less formally, Functions.
The Integrated Modeling Method (IMM) is unique in that it is the only modelling method that puts the Function Model (or Function Catalogue) at the core of all other models. This is the means by which all other business models can be fully integrated.
The stages in Function Modelling within IMM