Standby Configurations Without Containers

If you need to use a parallel or complex configuration as a path within a container, you can do the following: Create a diagram that models the required path configuration and analyze or simulate the diagram, then publish the results as a model. Create a URD that uses the model. In the container, add a contained block and assign the URD that you just created to it. Note that when you do this, results for the components within the path will not be available in your final results; only the fitted model is used.

You can also model a cold standby configuration (i.e., one where the component cannot fail when in standby) without using a standby container by using the Enable State Change Triggers option in the Block Properties window. This option allows you to specify the starting state of the block (i.e., off or on) and then specify events that will activate and/or deactivate the block during simulation. You can choose to activate or deactivate the block when items in specified maintenance groups go down or are restored. The current block does not need to be part of the specified maintenance group to use this functionality.

In addition, fault trees offer two gates that allow you to model standby configurations without containers: the priority AND (PAND) gate and the sequence enforcing (SEQ) gate.