For the earlier releases of Siebel CRM the Official Bookshelf (pdf version here) also contained a documentation of Business Processes to describe the activity flow within the Application from a starting point to a end point like the example below:
However, these have been discontinued from Version 7.5 for forth following releases. While some parts of the Oracle Organizations certainly maintained these afterwards as Assets, these were not general available as part of the official documentation anymore. For the new Fusion Application Software, which combines all previous separated products from PeopleSoft, e-Business Suite and Siebel into a single Application, the Business Process models are back. While they are not published on alongside the Official Documentation they are accessible via the Oracle Support Portal at the following site: Oracle Fusion Business Process Models: Homepage (Doc ID 1542019.1).
The above site lists the following Level 1 Business process area e.g. Marketing. Level 2 of the Business Process then describes the step in the process e.g. Develop Campaign and afterwards Execute Campaign. The Level 3 then contains a detailed activity flow in MS Visio e.g. Launch Campaign and Manage responses.
Business Process Area