Production Scheduling Capacity

I have a issue in Production Scheduling.  Most likely this is an issue in the Routings.

I have 7 machines in a department.  The routings only reference one of the 7 machines.  In PS, early test showed that we had greater capacity than in reality we actually have.   Although there are 7 machines, only 3 machines can run at a give once.  How can I get PS to understand this bottleneck?  Is there something I can set other than changing all the routings in this department to somehow tie the availability to a dummy resource where there are only 3 available at one time?  I realize that the routings are missing the operator resource that denotes