|
Depending on
the values of the transition conditions, the token follows either path A or path
B. |
Observe: a step precedes the divergence and the
transitions are in the branches.
Example:
Figure:
Or-Divergence
A jogger has once
to decide whether to continue or to stop the training and go for a drink. The
decision is represented by the transition conditions ‘tired’ or ‘not tired’.
Obviously the jogger can not follow both paths at the same time.
Correspondingly the token, representing the jogger, follows one of the two paths.
In an
OR-convergence two or more paths can be joined into one path. If path A is
marked, the transition ‘A-finished’ can be fired as soon as the condition is
true. If the step ‘continue’ is already
marked, there might result a problem, when this step can only be marked with
one token. These problems are investigated in more detail later on.
Observe: each
path ends with its transition condition leading into a common step. Graphically
the transition bar is placed before the convergence.
Example:
The
path to work of an employee and its arrival condition is generally independent
of the paths and conditions of other employees. One has to find a parking place
another has to path the entry control.