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 Schedule
			| Thursday, 30 January
 |  | 08:30-09:10 | Welcome-registration-coffee | B14-B15-B16 |  | 09:10-09:30 | Opening session | Amphi Cuccaroni |  | 09:30-10:30 | Plenary session  - Adam Letchford (Chair: Martine Labbé) | Amphi Cuccaroni |  | 10:30-11:20 | Coffee break | B14-B15-B16 |  | 11:20-12:40 | Parallel sessions |  |  | Multi-objective Optimization Chair: Sara Tari
 Room: E501
 | Health-care Chair: Véronique François
 Room: E502
 | Public Transportation Chair: Javier Duran Micco
 Room: E503
 | Global Optimization Chair: Olivier Rigal
 Room: E601
 | Analytics 1 Chair: Rafael Van Belle
 Room: E602
 |  | 12:40-14:10 | Lunch/ORBEL Board meeting | B14-B15-B16/E501 |  | 14:10-15:10 | Parallel sessions |  |  | Air, Rail and Multimodal Transportation Chair: Paola Paregrini
 Room: E501
 | Game Theory Chair: Lotte Verdnock
 Room: E502
 | Transportation of People Chair: Yves Molenbruch
 Room: E503
 | Multi-level Optimization Chair: Concepcion Dominguez
 Room: E601
 | Analytics 2 Chair: Vedavyas Etikala
 Room: E602
 |  | 15:10-15:50 | Coffee break | B14-B15-B16 |  | 15:50-16:40 | Parallel sessions |  |  | Sport Timetabling Chair: Dries Goossens
 Room: E501
 | Project Management and Scheduling Chair: Fan Yang
 Room: E502
 | Rich Routing and Graphs Chair: Alexandre Bontems
 Room: E503
 | Logistics Chair: Yuan Yuan
 Room: E601
 | Analytics 3 Chair: Jari Peeperkorn
 Room: E602
 |  | 16:50-17:30 | ORBEL general assembly | Amphi Cuccaroni |  | 19:00-20:00 | Cocktail | Bar Zango |  | 20:30-23:00 | Dinner | La Terrasse des Ramparts |  | Friday, 31 January
 |  | 09:30-10:30 | Plenary session - Miguel F. Anjos (Chair: Luce Brotcorne) | Amphi Cuccaroni |  | 10:30-11:20 | Coffee break | B14-B15-B16 |  | 11:20-12:40 | Parallel sessions |  |  | Automatic Configuration and Metaheuristics Analysis Chair: Kenneth Sorensen
 Room: E501
 | Real Life and Integrated Problems Chair: Jeroen Belien
 Room: E502
 | Warehouse Management Chair: Harol Mauricio Gamez
 Room: E601
 | Analytics 4 Chair: Noureddine Kouaissah
 Room: E602
 |  | 12:40-14:10 | Lunch | B14-B15-B16 |  | 14:10-15:10 | Parallel sessions |  |  | Orbel Award Chair: Jeroen Belien
 Room: E501
 | Optimization Chair: Julien Dewez
 Room: E502
 | Trucking Optimization Chair: Hatice Çalik
 Room: E601
 | Analytics 5 Chair: Diego Olaya
 Room: E602
 |  | 15:10-15:50 | Coffee break | B14-B15-B16 |  | 15:50-16:50 | Parallel sessions |  |  | Learning and Optimization Chair: Johan Van Kerckhoven
 Room: E501
 | Lot-sizing and Inventory Chair: Philippe Chevalier
 Room: E502
 | Rich Routing Chair: Cristian Aguayo
 Room: E601
 |  | 17:00-17:15 | ORBEL award and closing session | Amphi Cuccaroni |  | 17:15-18:30 | Closing cocktail | B14-B15-B16 |  | 
 |  Thursday 11:20 - 12:40 Multi-objective Optimization
 Room E501 - Chair: Sara Tari
 
 Thursday 11:20 - 12:40 Health-care
 Room E502 - Chair: Véronique François
 
 Thursday 11:20 - 12:40 Public Transportation
 Room E503 - Chair: Javier Duran Micco
 
 Thursday 11:20 - 12:40 Global Optimization
 Room E601 - Chair: Olivier Rigal
 
 Thursday 11:20 - 12:40 Analytics 1
 Room E602 - Chair: Rafael Van Belle
 
 Partisanship in everyday life: predictive modeling with Facebook like data Stiene Praet (University of Antwerp)
 Co-authors: Peter Van Aelst, David Martens
 
Success Prediction with Dynamic Time Warping-based Feature Engineering for Activity Count Data Steven Van Goidsenhoven (KU Leuven)
 Co-authors: Galina Deeva, Seppe vanden Broucke, Jochen De Weerdt
 
Unravelling Drop-out in Fully Asynchronous Subscription-based MOOCs: When is Drop-out Failure or Success? Wai Kit Tsang (Ghent University)
 Co-authors: Annelies Raes, Kristof Coussement, Dries Benoit
 
Valuing lead time in a periodic-review multi-period order-up-to inventory system Jente Van Belle (Vrije Universiteit Brussel)
 Co-authors: Tias Guns; Wouter Verbeke
 Abstract:
 Short lead times reduce exposure to demand uncertainty but generally also entail high production costs. de Treville et al. (2014) propose a real-options model for optimizing production (and sourcing) choices under demand uncertainty through an effective balance of production cost and lead time. They consider a single-period newsvendor problem in which lead time is modeled as an endogenous decision variable with demand uncertainty increasing in lead time and excess demand modeled as a foregone sales opportunity. The model allows to determine the required decrease (justified increase) in unit production cost to compensate for higher (lower) demand uncertainty exposure coming from an increase (decrease) in lead time.
In this paper, we propose several adjustments to this model that are necessary so that it can be used to analyze the effect of lead times in periodic-review multi-period order-up-to inventory systems in which excess demand is backordered. Under this commonly used inventory control policy, in each period t, (i) items produced in that period are added to inventory, (ii) demand is satisfied (fulfilled or backordered), (iii) the inventory position is reviewed, and (iv) the quantity to be produced at time t+h is determined based on the forecasted demand over lead time. Adjustments are suggested to take into account backordering costs and the shift from single-period to lead time demand forecasts.
We apply the adjusted model to a real case study in which sales history and open order data is available for producing demand forecasts. To this end, we rely on the closed-form Black-Scholes option pricing formulas. Historical data is used to calibrate the model parameters which allows us to take into account the effect on demand uncertainty of the arrival rate and clustering behavior of the open order data.
Finally, we also propose a data-driven counterpart of the model by relying on sample average approximation via inventory simulations. This alternative approach allows to consider inventory systems that make use of nonparametric distributions to determine optimal production quantities but is computationally more intensive than the real-options model.
 
 Thursday 14:10 - 15:10 Air, Rail and Multimodal Transportation
 Room E501 - Chair: Paola Pellegrini
 
 Thursday 14:10 - 15:10 Game Theory
 Room E502 - Chair: Lotte Verdnock
 
 Thursday 14:10 - 15:10 Transportation of People
 Room E503 - Chair: Yves Molenbruch
 
 Thursday 14:10 - 15:10 Multi-level Optimization
 Room E601 - Chair: Concepcion Dominguez
 
 Thursday 14:10 - 15:10 Analytics 2
 Room E602 - Chair: Vedavyas Etikala
 
 Thursday 15:50 - 16:50 Sport Timetabling
 Room E501 - Chair: Dries Goossens
 
 Thursday 15:50 - 16:50 Project Management and Scheduling
 Room E502 - Chair: Fan Yang
 
 Thursday 15:50 - 16:50 Rich Routing and Graphs
 Room E503 - Chair: Alexandre Bontems
 
 Thursday 15:50 - 16:50 Logistics
 Room E601 - Chair: Silia Mertens
 
 Thursday 15:50 - 16:50 Analytics 3
 Room E602 - Chair: Jari Peeperkorn
 
 Friday 11:20 - 12:40 Automatic Configuration and Metaheuristics Analysis
 Room E501 - Chair: Kenneth Sorensen
 
 Friday 11:20 - 12:40 Real Life and Integrated Problems
 Room E502 - Chair: Jeroen Belien
 
 Friday 11:20 - 12:40 Warehouse Management
 Room E601 - Chair: Harol Mauricio Gamez
 
 Friday 11:20 - 12:40 Analytics 4
 Room E602 - Chair: Noureddine Kouaissah
 
 Friday 14:10 - 15:10 Orbel Award
 Room E501 - Chair: Jeroen Belien
 
 Friday 14:10 - 15:10 Optimization
 Room E502 - Chair: Julien Dewez
 
 Friday 14:10 - 15:10 Trucking Optimization
 Room E601 - Chair: Hatiz Çalik
 
 Friday 14:10 - 15:10 Analytics 5
 Room E602 - Chair: Diego Olaya
 
 Friday 15:50 - 16:50 Learning and Optimization
 Room E501 - Chair: Jorik Jooken
 
 Friday 15:50 - 16:50 Lot-sizing and Inventory
 Room E502 - Chair: Philippe Chevalier
 
 Friday 15:50 - 16:50 Rich Routing
 Room E601 - Chair: Cristian Aguayo
 
 
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	  	|  | ORBEL  - Conference chairs: Diego Cattaruzza and Maxime Ogier 
 
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