How to close an order header when all the lines are closed

Hi

My question is with regard to the closing the order header status to 'Closed' when all its lines are in 'closed' status.

I remember that usually we close the order header once in a month if all its lines are closed. I also read from metalink that we can customize this order header close duration in the workflow for ech order type.

Can someone tell me what is the exact parameter which controls the header closure once in a month for all the order type?

Appretiate any help.