( discussed below). Clients have contacts within their companies that CMS employees must utilize. For example, the accounting department must know a client‘ s billing contact in order to know where to send the bill. Maintenance engineers must know a client‘ s systems engineering contact to know with whom to speak when a problem arises. CMS‘ s sales representatives must know a client‘ s sales contact to determine who is responsible for the buying decisions at a client site. Although only these three contact ― types ‖ are currently used by CMS, it is foreseeable that additional contact types might be useful as the company expands into other parts of the world. Currently, a client has only one billing contact, one systems engineering contact, and one sales contact at any given time. This structure is not expected to change( that is, more than one billing contact per client as of a particular point in time is not anticipated); however, it is important to retain all contact information over time. That is, when one contact is replaced by another contact, it is essential to retain information about the original contact. For example, assume an invoice is sent to Contact A, who is later replaced by Contact B. If the invoice is lost, CMS must have an audit trail to show that it was sent to Contact A( who was the known contact for the client at that time). Clients can have one or more contracts with CMS to provide a variety of consulting services. For example, a single client might have one contract for maintenance of an existing system and also have another contract( sometimes called a work order by the sales force) for the development of a new system. Some clients are billed based upon negotiated contracts, which stipulate a pre-determined amount for charges regardless of the number of hours that employees actually work on the contracts. Such contracts are called ― fixed price ‖ contracts. Other clients are billed based on the total number of hours provided by CMS employees multiplied by a rate per employee type per employee hour. These arrangements are called ― T & M