3 présentations

• 
  10h30 - 10h55

  Auction-based centralized procurement of TL services

  • Monia Rekik, prés., Université Laval
  • Intissar Ben Othmane, Université Laval
  • Sehl Mellouli, Université Laval

  Traditionally, a shipper, that needs to outsource its transport operations to external carriers, runs a transportation auction on its own. Carriers then submit bids in each auction separately, either sequentially or simultaneously, with no guarantee that all the submitted bids would win in all auctions. We propose a novel centralized transportation procurement auctions in which shippers collaborate by presenting their transportation requests to the same market. Carriers are thus offered the possibility to submit their bids to a unique auction and to combine shipping requests of different shippers. We investigate the benefits/drawbacks of such a mechanism from the carriers’ perspective through an exhaustive experimental analysis. Different economic and environmental performance measures are evaluated.

• 
  10h55 - 11h20

  A two-stage stochastic programming approach for the bid construction problem with stochastic contracts

  • Farouk Hammami, prés., CIRRELT
  • Monia Rekik, Université Laval
  • Leandro C. Coelho, Université Laval

  In combinatorial auctions for the procurement of transportation services, bid construction problems (BCPs) have been studied since the 1990s. A BCP must be solved by each carrier participating into a transportation procurement auction in order to choose the set of contracts that are the most profitable to bid on and the associate bid price. These decisions are generally made under uncertainty due to other competing carriers’ offers. In this work, we propose a two-stage stochastic programming approach with recourse to handle uncertainty on the contracts winning probabilities. Preliminary results will be presented.

• 
  11h20 - 11h45

  A robust optimization approach for the WDP with uncertainty on shipment volumes and carriers' capacity

  • Issmail El Hallaoui, prés., GERAD, Polytechnique Montréal
  • Amine Amrouss, Université de Montréal
  • Monia Rekik, Université Laval
  • Nabila Remli, CIRRELT

  We address the winner determination problem (WDP) for TL transportation procurement auctions under uncertain shipment volumes and uncertain carriers' capacity. The proposed approch extends an existing two-stage robust formulation proposed for the WDP with uncertain shipment volumes. We identi fy and theoretically validate a number of accelerating strategies to speed up the convergence of a basic constraint generation algorithm proposed in the literature. Experimental results prove the high computational performance of the proposed new algorithm and the relevance of considering uncertainty on the carriers' capacity when solving the WDP.