FAQ for Bizagi Modeler

This page has some Frequently Asked Questions and Answers for the Bizagi Modeler used in the BPMS assignment.

How to model an OR-split and OR-join?

Models with OR-split or OR-join have a different semantic with simulation. Consider for instance the model as depicted below:

If we look at the simulation options, then we can see it is not possible to let 90% of the cases have luggage and 30% of the cases have a bike.

Therefore, in this assignment the OR-split and join should be modeled as:

Now we have the option so have the desired percentages for each of the branches.

Bizagi simulation fails

The Bizagi simulation fails with an error message such as:

  • “The simulation has failed. Please ensure that your models is compliant to the BPMN 2.0 standard and that it is supported by the Simulation engine.”
  • Or a simulation run starts but then suddenly stops.
  • Or the simulation completes, but then fails to generate the simulation report.

The Bizagi simulation assumes a number of properties on the model to hold that are not explicitly mentioned:

  • Make sure your model is valid BPMN and no connections are disconnected.
  • Make sure any gateway (parallel, choice) has either multiple incoming OR multiple outgoing edges. If the gateway has both, split the operator into two operators. If the gateway has neither, remove it.
  • Make sure the distributions used for the various tasks cannot become negative, i.e., the simulation engine fails it it draws a negative value for a duration.
  • Make sure all names and labels in the model (tasks, gateways, events, swimlanes, etc.) have a valid (non-empty, no special characters (no backslash \ or slash /) label.
  • Sometimes a reboot of Bizagi might help…

Is there an easy way to connect different constructs in Bizagi?

Yes there is. When selecting a constuct (task, gateway, etc.) you have the following image:

Dragging and dropping, for instance, the square will create a new activity connected to this activity. Dragging and dropping, for instance, the square on a gateway will create a connection between this activity and that gateway.

In simulation view, I do not see the simulation steps, I cannot set time and resource information, and I get an error message.

  • If you have the following GUI in simulation mode, which sometimes gives the following error:

The Petri Net generated from a BPMN model (XDPL) contains a disconnected task named “t_ev_Message”.

This is a task without a name but with a message trigger. Bizagi sometimes does not correctly delete tasks (with triggers). As a result of this, the BPMN model does not (visibly) contain an empty, disconnected task but the XPDL export does.

The solution is simple: open two instances of Bizagi, one with a new, completely empty model (e.g. delete the default swimlane) and one with the current model. Then select everything in the original model (CTRL+A) and copy-paste that in the new, empty one. This new model (which of course looks exactly the same) can then be exported to XPDL. The XPDL does not contain the disconnected task and can be verified with ProM again. The disconnected task should no longer be there.

Other Resources

If you need help, you might also try the following resources: