Multi-criteria Negotiation in Multi-Agent Systems

Abstract: Negotiation is a kind of decision making where two or more parties jointly search a space ofsolutions with the goal of reaching a consensus. This search usually is a single dimension process where thedifferent agents, involved in the negotiation process, mutually adapt their price offers in order to reach theirgoals (to sell or to buy a good). However, this process is inflexible and often unrealistic because more thanone single issue has to be negotiated in order to find out an adequate agreement. In this paper we introducea multi-issue negotiation protocol for one-buyer-to-many-sellers interaction. The paper is also enhancedwith an application example that illustrates the negotiation process and shows how it can be useful both asa product brokering and as a market brokering tool.Keywords: Negotiation, Multi-issue negotiation, Electronic Commerce. I - Introduction Most of the well known negotiation protocols deal with a single dimension (usually the price). Moreover,Wellman [Wel99] also says that the preferences’ reduction to the price single figure is what characterises themarket. However, this seems to be a bit simplistic and unrealistic in the electronic commerce framework.In this paper we are going to focus our attention on the kind of negotiation that takes place in an electronicmarket involving one buyer and many merchants that are potential sellers. In fact, we will use the traditionalConsumer Buying Behaviour Model (CBB) that is also used and enhanced to accommodate the software agentsconcepts as it is done by [Gut98a]. CBB encompasses six main stages: Need Identification, Product Brokering,Merchant Brokering, Negotiation, Purchase and Delivery, and finally Service and Evaluation. Currently,Electronic Commerce agent mediated systems try to automate, at most, three of these stages (Product andMerchant Brokering as well as Negotiation). Here in this paper we are most concerned with the use of SoftwareAgents for a rich (multi-dimensional) and flexible (adaptive) design of the Negotiation phase protocol.However, as we will see later, this negotiation protocol can also be seen as a product brokering stage once thebuying agent can also use it as a market search process.Negotiation is a kind of decision making where two or more parties jointly search a space of solutions with thegoal of reaching a consensus [Ros94]. Some authors [Vul98] advocate the use of auction protocols for agent-mediated EC, arguing that they are widely recognised by economists [Moo92] as the most efficient way ofresolving one-to-many negotiations.Other authors point out the limitations of auctions’ protocols and seek for more flexible negotiation models[Gut98b]. They stress out that online auctions are in fact less efficient and more hostile than it would be desired.