Use case

To demonstrate the mediator design pattern, we will emulate a widget production system that includes a hopper for parts, a starter to start the system, an assembly system to combine hopper components, an accelerator, and an emergency break to manage the speed of the system.

There are inter-relations between the various components for our mediator to manage. These inter-relationships are detailed here:

Widget production system inter-relationships

 

As you can see from the table, there are 16 inter-relationships among the 5 system components for the mediator to manage.