I am currently working for IT service industry project majorly dealing with government clients. The new projects are created in PS and subsequently a contract has to be created in SD(with WBS element) and billed without delivery. The delivery part is taken care by MM. SD module role is to to billing for these projects. We are planning to create service material as a project and then complete the sales cycle. Now my doubt is that which type of contract type shall I use for this process, can we do direct billing for this contract or shall I create a release order and then do billing.