LeCouteauSuisse provide information on queues through performance counter of Windows. Each queue have a performance counter that give the number of event inside the queue. To look this counters :

1. Launch the Performance Monitor
2. Clic on "Add counter", find the name "CoffeeSupplyChain" (this is the name of your service), clic on "Events"
3. We want to supervise events generated by coffee machine, we look at 2 queues, the generator queue and the receiver queue. Select counter named "generator machinealert" and "receiver sendalert of machinegroup" and add these counters.
4. Send alerts and look at queue counter. Bellow you can see several events in the receiver sendalert :