Occurrences
An Occurrence is an event that happens over time. Items and Parts are categorized as structural occurrences while Actions are categorized as behavioral occurrences.
Creating an Occurrence
To create an Occurrence from the System Structure Diagram toolbar:
1. On the System Structure Diagram toolbar, click the Occurrence 
button.
button.2. Click on the diagram canvas to create an Occurrence.
To create an Occurrence from the context menu in a Package browser:
• Right-click on the element for which you want to create the Occurrence, and select > > .