4.13 CPI is a technique which should have become normal practice years ago. In conjunction with the preparation of a full matrix of documents, its use should be made part of the Conditions of Engagement of the designers. If, as a result of the client's own instructions or through some problem on the part of the design team, the design drawings and specifications are not fully complete, and provisional sums are used, the consultants must make the client aware of the risks of incomplete design. The consultants should get specific approval through a "signing off" procedure, whereby the client is aware of the consequences for the construction programme in terms of possible cost and delay Throughout the process, the emphasis must be on meeting the client's needs and keeping the client fully informed of potential risks.