When people complain about each other, make them work together.

How many times do you hear one department of your company use another department as the reason why they cannot be successful? This indicates a need for change. I find blame is the path of least resistance and then the tennis match begins, swatting the reason why things are not working back and forth.

If both parties wprk on the same side of the net, then what?

Thus, one of my maxims: When people complain about each other, they should work together and share accountability. It may fly in the face of all your company's procedures and org structure but I find people generally want to succeed and usually will if barriers are removed.