The IDEF (Integrated DEFinition) family of methods promote a structure approach to process modelling and analysis. IDEF0 is a process modelling method that was developed from a well established graphical language (the Structured Analysis and Design Technique - SADT) for the US Air Force. It is a top-down, hierarchical method of analysing activities. The analysis consists of an ordered collection of diagrams, text and index, all cross-referenced to one another.

The method is more rigorous and structured than the process mapping previously outlined. This overview is included here because the IDEF0 method is one that is widely used but anyone considering this approach is recommended to undertake further study or training.

Activities are described in terms of their inputs, outputs, controls and mechanisms (ICOM). The technique is sometimes called ICOM although the word mechanisms is frequently replaced by 'resources' which is more meaningful in our context.

Activities are decomposed in a similar way to that described earlier. The rules of IDEF0 however state that there can be no more than six sub-processes on each diagram. A criticism of IDEF0 models is that they are sometimes too concise to be readily understandable to non-experts. Other rules govern the graphical syntax, the fact that all functions require at least one control and the need for a purpose and viewpoint statement for each model.

This technique was used by Northumbria University in its Administrative Workflows Analysis Project. Examples of diagrams created to analyse the enrolment process at Level 1, Level 2 and Level 3 are included in this Kit.

We identified that IDEF0 is a top-down approach. When designing a future process for the 'To be' stage you are likely to take a top down approach and continue refining the process to the required level of detail to cover all eventualities. When modelling the 'As is' state however you may often take a bottom-up approach collecting detail of what people do on the ground and grouping related functions. It is possible to build up the IDEF0 model in this way.