An Analysis diagram is a simplified Activity diagram, which is used to capture high level business processes and early models of system behavior and elements. It is less formal than some other diagrams, but provides a good means of capturing the essential business characteristics and requirements.
Robustness diagrams, used extensively in ICONIX, can be created as Analysis diagrams.
Example Diagram Example Analysis Diagram
Select Analysis diagram elements and connectors from the Analysis pages of the Toolbox.