Towards Effective Negotiation Support in Electronic Marketplaces Mareike Schoop and Christoph Quix Informatik V (Information Systems), RWTH Aachen, 52056 Aachen, Germany schoop,quix @informatik.rwth-aachen.de Abstract Electronic marketplaces are an upcoming model for business-to-business electronic commerce. In elec- tronic marketplaces, companies can offer their services and products. Other companies can search for products in the marketplace to find new business partners. Once contact between two business partners has been established, a negotiation starts in order to reach a formal agreement on their business relation. During the negotiation, documents and messages are exchanged. Systems for electronic markets support auctions and similar negotiation models rather than peer-to-peer negotiations. However, peer-to-peer negotiations are common in most business domains. In this paper, we propose a conceptual model to support electronic negotiations by extending the model of document management systems with commu- nication models. The idea is based on the observation that the exchange of messages is closely related to the evolution of documents. 1 Introduction Electronic commerce (EC) is turning from a vision into reality. There is a large number of EC approaches both from academic and industrial backgrounds [12]. Mostly, business-to-consumer EC is supported. When turning to the area of business-to-business electronic commerce (BtB EC), a number of specific issues can be observed. For example, the early stages of an EC process become very important as companies look for new suppliers and aim at distinguishing themselves from other competitors. Furthermore, trust plays an important role since the internet enables business connections with unknown companies that might not be trustworthy. In addition, electronic negotiations with specific characteristics for BtB EC must be made pos- sible to allow structured and effective interactions between the business partners. Finally, integrated systems are required. The new components dealing with EC (i.e. starting from an intelligent search, supporting elec- tronic negotiations, monitoring the fulfilment of contracts) need to be integrated with the existing business processes, e.g. logistic and management systems of the companies. Electronic marketplaces (EMs) are an upcoming approach to support BtB EC. EMs enable companies to present their products and services in a uniform marketplace which can be searched by other companies looking for specific products and/or new business partners. Such solutions are for example realised by Ariba [1] and CommerceOne [2]. These systems support the first stage of an EC process, i.e. establishing new business contacts. The second phase of an EC process is the negotiation. In this paper we will concentrate on the phase of negotiation support in an EM. In contrast to most approaches dealing with electronic negotiations, we will not consider the support of auctions or similar settings (as, e.g. [5, 14]) since we see them as less appropriate for peer-to-peer negotiations in BtB EC. The current status of electronic negotiations is that usually electronic forms of catalogues are presented to a customer which means that the customer can either decide to order for the price mentioned or to leave it altogether. No explicit support of interactions dealing with negotiation steps is offered. We argue that such support is required and, consequently, we will present our approach that provides the basis for effective negotiation management. Conventional negotiations begin with a phase of request or offer followed by counter-offers and bargain- ing before finally reaching an agreement (or terminating the negotiation in case of severe disagreements). We propose similar structures for electronic negotiations and our approach is as follows. Problems observed to occur in negotiation processes have been classified according to a powerful framework based on commu- nication theories [7, 8]. In this paper, we will specify the features of “ideal” systems that exploit the potential