The SoRs is a document prepared by clients, or in the verbal statements communicated to supplies, it is based on the user functional needs. These user requirements are converted into performance requirements, which can be explicit or implicit. Such document should include information about what is essential to the client. SoRs will take different forms depending on the kind of client and what is being procured, at what phase of the Life Cycle or where in the supply chain a document is being used. The SoRs should be, dynamic, not static, and should include more and more details as projects proceed. This document should be prepared at different levels of granularity, how detailed the documentation is at each stage depends on the complexity of the project and on the procurement route chosen for the project.
