2-2.3 Statement of Work The SOW should be provided in the RFP when purchasing a service, rather than an end product, because an SOW typically illustrates the characteristics of how a deliverable-oriented project will be conducted. SOWs may include specifications or product descriptions; whenever standard or modified commercial products will meet Postal Service requirements, product descriptions must be used instead of specifications. SOWs must describe the work as precisely as possible and in enough detail to allow a best value decision and effective contract performance. An SOW typically comprises: Project scope. Key assumptions. Postal Service responsibilities. Supplier responsibilities. Deliverable materials. Completion criteria. Estimated schedule. Additional requirements (specific to a particular offering or transaction). Deliverable materials guidelines. Project procedures (such as the change control procedure, deliverable materials acceptance procedure, and escalation procedure). After determination of award, SOWs are the standard for measuring performance and are used by both parties to determine rights and obligations under the contract.