The primary function of a junction symbol is to supply the flow logic of the process described in the IDEF3 Process Flow diagrams. When you draw IDEF3 precedence links to and from junctions in an IDEF3 diagram, System Architect determines whether the junction is ‘Fan-In’ or ‘Fan-Out’. You may also specify simulation properties of the junction.
Specifying the type of junction
Within the Definition dialog of a junction there is a Sim Symbol tab that will enable you to associate the type of junction logic that will be used. The following types are available:
▪Attribute
▪Object Type
▪Probability
▪Shortest Queue
▪Time in Model
When the junction type has been established, you must select the Apply button to change the properties in the junction’s Definition dialog. Appropriate properties for the type of junction will become available on an appropriate tab, which will appear.
The junction type, and corresponding logic of the flow, will be notated on the junction symbol on the diagram. AND will display as a & mark, OR as O, and XOR as X. Certain routing options may not be available to certain Logic settings.
1 Open the J1 junction definition. On the Symbol tab set the Logic to XOR. Press the Apply button (bottom right of the dialog). (For this particular change, the dialog does not change – the Sim Fan Out tab remains.)
2 Select the Sim Fan Out tab and make sure the Outflow Routing is set at Probability.
3 Press OK.
Specifying the probability of outgoing flow lines
1 Open the IDEF3 Precedence Link called Canceled Order by double-clicking on it; alternatively, right mouse-click on it and select Edit from the floating menu.
2 Select the Sim Symbol tab and set the Junction Type to Probability. Press the Apply button. This will reveal a tab in the dialog called Sim Probability.
3 Set the Probability to 5. We are saying that on average, there is a 5-percent probability that the order will be canceled by the customer.
4 Press OK to accept the changes.
Since the Probability percentages must add up to 100%, we will need to set the other flow coming out of the junction, Ensure Stock Link, to 95.
5 Open the IDEF3 Precedence Link called Ensure Stock.
6 Select the Sim Symbol tab and set the Junction Type to Probability. Press the Apply button. This will reveal a tab called Sim Probability.
