Example Description
-Course registration-
Consider a situation where a student has to choose courses to study before they register for the term. The lecturers also have got to volunteer for the courses they are going to teach so the registrar can compile a list of courses to be chosen by the students.

Figure 1: Course registration
Users can now animate the above description to view the various state changes of the actors as they perform their respective events. For instance the first animation window is:

Figure 3: First animation window (registrar is secondary actor)
Figure 3 shows the lecturer in an initial state; ready to volunteer for courses to teach, and the registrar in the initial state. If this is not the desired behaviour, that is, if say it is the student who interacts with the lecturer when the lecturer is about to volunteer for course, then the description should be edited so that the student is the secondary actor for the first available event.

Figure 4: Student as secondary actor for first event
The first animation window shows that the student (not the registrar) is at initial state this time.

Figure 5: Student is now at initial (not the registrar)