The document is a manual for the purchasing and contract administration divisions of the City of Thornton. It provides guidelines and procedures for open purchase orders, which are used when the exact amount for supplies or services on a project cannot be determined prior to completion. The policy states that open purchase orders must adhere to competitive solicitation requirements, unless there is written justification for a noncompetitive award. The document outlines the procedures for submitting open purchase requisitions, including providing necessary information such as requisition number, requestor's identification, requisition date, confirming purchase order number (if applicable), ship to location, department, and G/L account to charge. It also includes optional fields for additional information such as suggested vendor name, approval login ID's, and comments/special requirements. The document emphasizes the importance of timely payment authorization and warns against intentionally withholding payment authorization, unless instructed to do so by the purchasing agents. The manual concludes by stating that the originating department/division will receive a copy of the finalized blanket purchase order, which is used for authorization of payment. The purchase order is valid from a specified starting date to an anticipated ending date, and it is not to be used beyond that period.