System behaviour can be described under the item <behaviour> for the part type. Behaviour itself can be described in various ways:
 
Description in a CASE-Tool
Describing behaviour in a CASE-Tool entails making a reference to the CASE-Tool description under the point <behaviour>. A context diagram can also be included (see SA Method .
 
Description in the current SGML document
For a description of behaviour in the document itself, the following outline should be used:
1.
 
Description of system behaviour
2.
 
Description of system environment
Here, the external systems and the input/output sizes are described. A context diagram can also be included.
3.
 
Operating modes
All the relevant operating modes of the system within this project version must be defined here. Referencing of the states defined here is carried out at the appropriate place.
4.
 
Functions
All functions are listed here. The input/output, connections and flow of information, assigned operating states, assigned components and tests appropriate for the function are described for each function. It is possible to build a function hierarchy like these example:
4.1 Function 1
4.1.1 Function 1.1
4.2 Function 2
...