The Integrated Modeling Method (IMM) is the only truly integrated business modeling method.
IMM achieves this integration because it puts the Function Model at the heart of the business. All other models can (and should) be derived from the Function Model.
The very first stage in good Business Systems Modeling should be to be to identify and model WHAT the business OUGHT to be doing.
Before computerising any Business Functions it is essential to identify and model the data used or created by these Functions and its relationship to other data items (or data entities) within the business.
Information Flow Modeling
When you need to know how information flows around, into and out of the business, Information Flow Modeling is the technique to use.