You can create SysML models with the SparxSystems Enterprise Architect Ultimate and Systems Engineering editions. This SysML capability can also be added to a Professional or Corporate installation. Version 9 supports SysML 1.2. Version 10 -- now out in Beta (Nov. 10, 2012) -- supports SysML 1.3.
In SysML, a requirements document is drawn a box for a requirements and connectors for relating requirements. The connectors are used to denote one requirement as expanding another (Derive, Refine) or containing another (Containment). SysML uses an "id" attribute to hold the requirements identifier and "text" atttribute to hold the text of the requirement. These attributes are Tagged Values in EA.
This SysML diagram shows a package Specifications that contains a requirement "Place order". "Place order" is further broken down into other requirements: "Browse catalog", "Select item", etc. This containment relationship is shown using a connector with a ball on the end.
|A SysML 1.3 Requirements Diagram in SparxSystems 10|
In the Project Browser, the containment is reinforced by dragging the child requirements (Browse catalog) over the parent (Place order) so that they are nested. This greatly reduces the clutter in the Project Browser with a large number of requirements.
|Project Browser Showing SparxSystem 10 SysML 1.3 Requirements|