M. Ali et al. (Eds.): Contemporary Challenges & Solutions in Applied AI, SCI 489, pp. 35–40. DOI: 10.1007/978-3-319-00651-2_5 © Springer International Publishing Switzerland 2013 Winner Determination in Combinatorial Reverse Auctions Shubhashis Kumar Shil, Malek Mouhoub, and Samira Sadaoui Abstract. Since commercially efficient, combinatorial auctions are getting more interest than traditional auctions. However, winner determination problem is still one of the main challenges of combinatorial auctions. In this paper, we propose a new method based on genetic algorithms to address two important issues in the context of combinatorial reverse auctions: determining the winner(s) in a reasona- ble processing time and reducing the procurement cost. Indeed, not much work has been done using genetic algorithms to determine the winner(s) specifically for combinatorial reverse auctions. To evaluate the performance of our method, we conducted several experiments comparing our proposed method with another me- thod related to determining winner(s) in combinatorial reverse auctions. The expe- riment results clearly demonstrate the superiority of our method in terms of processing time and procurement cost. 1 Introduction An auction is a market scenario in which bidders compete for item(s). In tradition- al auctions, an individual item is auctioned separately, which leads to an ineffi- cient allocation and processing time [7, 10]. Combinatorial auctions have been proposed to improve the efficiency of bid allocation by allowing bidders to bid on multiple items [7, 10]. These auctions provide a combinatorial allocation that mi- nimizes the procurement cost and running time [5, 7, 10]. They have been used in various real-world situations [1] such as resource allocation with real-time con- straints [10], sensor management [9, 11], supply chain management [12] and computer grids [2]. A combinatorial auction problem is actually a winner determi- nation problem [4]. Winner determination is still one of the main challenges of combinatorial auctions [10]. Indeed, determining the winner(s) in combinatorial Shubhashis Kumar Shil ⋅ Malek Mouhoub ⋅ Samira Sadaoui Department of Computer Science, University of Regina, Regina, SK, Canada e-mail: {shil200s,mouhoubm,sadaouis}@uregina.ca