A master vendor agreement is a contract between a company and vendor that sets terms and conditions the latter must follow while vending the company's product. A statement of work, or SOW, seeks to define liabilities, responsibilities, and work agreements between two parties, usually between a client and parties.The SOW authorizes Agency to commence performing any Services as of the Effective Date. Contractor shall also identify any expected variances between the SOW requirements and how Contractor will complete the project. Vendor Performance Reporting. 111. Overview. 111. Acting Under Secretary of the Air Force Shon Manasco, along with Chief Master Sgt. San Antonio, TX 78230 United States. Source.