"The request for proposal (RFP) is the heart of a library system purchase and represents a coordinated effort between members of the library staff to develop a coherent statement of the library’s mission, needs, and expectations. [It] is a tool used by institutions to purchase products and services by promoting competitive proposals among vendors. The RFP’s use, though, extends beyond an institution’s procurement process. It, along with the winning vendor’s response, serves as the foundation for the working relationship between institution and vendor. This foundation allows both parties to operate under the same agreed-upon solutions, requirements, and schedules set forth in the request and proposal."
Waller, Nicole. 2009. "Chapter 1: What Is An RFP And Why Is It Worth Your Time?".Library Technology Reports 39 (4): 7-11.
Waller, Nicole. "Model RFP for Integrated Library System Products." Library Technology Reports 39, no.4 (2003). http://dx.doi.org/10.5860/ltr.39n4
Westfall, Micheline, Justin Clarke, and Jeanne M. Langendorfer. "Selecting a Vendor: The Request for Proposal (RFP) from Library and Vendor Perspectives." Serials Librarian 64, no. 1-4 (January 2013): 188-195. doi:10.1080/0361526X.2013.761031.
Additional resources can be found by doing a web search for <sample rfp for integrated library system> or searching WorldCat for <sample rfp libraries>