As previously described, scenarios allow us to represent different paths that may occur through a business process.

Although most of these paths will be based on actions taken by the various roles involved in the scenario, occasionally scenarios also need to be able to indicate what should happen when no action occurs - i.e. a 'time out' situation.

As we are building up our scenario, if appropriate, we can introduce an 'elapsed time' event into the scenario. So if we start with an interaction to the CreditAgency, e.g.

We then want to be able to define a scenario to represent the case where the CreditAgency does not respond within a certain time period. To add an 'elapsed time' event, simply select the "Elapsed Time" icon from the palette and select the vertical location on the diagram where the event should be added. It will introduce a region horizontally across all roles.

This can be used to document that the maximum timeout should be 2 minutes (120 seconds), and also used during simulation/service testing to ensure the implementation correctly handles the timeout.