What document does a customer send when they want to purchase a service rather than a product, often considering cost and time?

The document a customer sends when they want to purchase a service rather than a product, especially when considering factors such as cost and time, is a Request for Proposal (RFP).

An RFP is a formal document that outlines the specific services needed and invites service providers to propose how they would meet those needs. It includes details about project requirements, timelines, expected outcomes, and budget considerations. By issuing an RFP, the customer can evaluate different proposals and select the service provider that offers the best solution for their requirements and constraints.

In contrast, a Request for Quotation is typically used when the buyer needs pricing information on specific services or products but does not typically include broader project proposals or detailed service descriptions. An Invitation for Bids is generally used in procurement processes where competitive bids for a project or service are sought, usually focused on price rather than the specific approach to the work. A Request for Information is a preliminary step that gathers information about the capabilities of potential service providers without specifically soliciting proposals for a contract.

Thus, the RFP process allows for a more comprehensive evaluation of potential suppliers based on their proposed methodologies, enabling informed decision-making.