I'd say most of the time, there is one company but several contacts within that company. What will distinguish one from the other is often a specific job, specific equipment or perhaps a PO. I think it could be said that if you put all the tables and relationships in place without first nailing down the process and who fits where, that you're putting the cart before the horse.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.