You can create a Fork State on a State Diagram or through a Modeler browser. Define a Fork State's incoming and outgoing Transitions on a State Diagram.
To create a fork state on a state diagram:
1. On the State Diagram toolbar, click the Fork State button.
2. On the State Diagram, click in free space or within a Sequential State.
3. If you want the Fork State to be horizontal:
a. Right-click the Fork State, and then click View Options.
b. Select the Horizontal option, and then click OK.
To create a fork state in a Modeler browser:
1. Right-click the State Machine or Sequential State that is to own the Fork State, point to New, point to Pseudo State, and then click Fork State.
Fork State button.