routing numbering

Hello,

I am trying to understand the concept of the routing numbering. As per my understanding a routing group number is not plant specific. But a counter in the group is plant specific. Also for a particular counter one can assign materials from different plants. Also each counter can have operations in different plants. Am I right in my understanding ? Why would one have materials from different plants assigned to a counter and why would one have different operations in different plants in

a counter ?

Thanks

GS