A reverse auction (also called procurement auction, e-auction, sourcing event, e-sourcing or eRA) is a tool used in industrial business-to-business procurement. It is a type of auction in which the role of the buyer and seller are reversed, with the primary purpose to drive purchase prices descending. In an ordinary auction (also known as a forward auction), buyers compete to obtain a good or service. In a reverse auction, sellers compete to obtain business

Reverse Car Auction is a tool used by many purchasing and supply management organizations for spend management, as part of strategic sourcing and overall supply management activities.In a typical auction, the seller puts an item up for sale. Multiple buyers bid for the item and depending on the nature of the auction (English or Dutch), and one or more of the highest bidders buy the goods at a price determined at the conclusion of the bidding.In a reverse auction, a buyer contracts with a market maker to help make the necessary preparations to conduct the reverse auction. This includes: finding new suppliers, training new and serving suppliers, organizing the auction, managing the auction event, and providing auction data to buyers to facilitate decision making.The market maker, on behalf of the buyer, issues a request for quotation (RFQ) to purchase a particular item or group of items (called a "lot"). At the designated day and time, several suppliers, typically 5-20, log on to the auction site and will input several quotes over a 30-90 minute period. These quotes reflect the prices at which they are willing to supply the requested good or service.Quoting performed in real-time via the Internet results in dynamic bidding. This helps achieve rapid downward price pressure that is not normally achievable using traditional static 3-quote paper-based bidding processes. The prices that buyers obtain in the reverse auction reflect the narrow market which it created at the moment in time when the auction is held. Thus, it is possible that better value - i.e. lower prices, as well as better quality, delivery performance, technical capabilities, etc. - could be obtained from suppliers not engaged in the bidding or by other means such as collaborative cost management and joint process improvement.The buyer may award contracts to the supplier who bid the lowest price. Or, a buyer could award contracts to suppliers who bid higher prices depending upon the buyer's specific needs with regards to quality, lead-time, capacity, or other value-adding capabilities. However, Reverse Car Auctionbuyers frequently award contracts to incumbent (i.e. current) suppliers, even if prices are higher than the lowest bids, because the switching costs to move work to a new supplier are higher than the probable savings that can be realized. This outcome, while very attractive to buyers, is often strongly criticized by both new and incumbent suppliers

Buyers, sellers, and market makers should adhere to auction rules and industry codes of conduct for the use of reverse auctions, if they exist. Problems arise when one or more parties fail to kowtow to auction rules. This can range from simple cries of "foul" to litigation.Buyers should not assume that reverse auctions will, in every case, deliver savings - either on a unit price or total cost basis. Reverse auction savings can range from negative (i.e. it costs the buyer money) to neutral (i.e. no savings) to positive savings.