Informs 2015

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INFORMS Philadelphia – 2015
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4 - Can Time Buffers Lead to Delays? The Role of
Operational Flexibility
Milind Sohoni, Associate Professor Of Operations Management
And Sr. Associate Dean Of Programs, Indian School of Business,
Gachibowli, Indian School of Business, Gachibowli, Hyderabad,
Pl, 500032, India, , Sanjiv Erat
In operating systems where the feasible start time of activities is uncertain, the
actual buffers for conducting the activities are distinct from scheduled buffers. We
study how, and why, do these buffers affect operating performance? We propose a
theoretical model and evaluate its empirical content and predictions using airline
industry data. Our main result shows that both buffers impact performance and
their effects are moderated by flexibility. Thus ex-ante plans must consider
flexibility.
TB67
67-Room 201A, CC
Advances in Vehicle Routing Problem and its Variants
Sponsor: TSL/Freight Transportation & Logistics
Sponsored Session
Chair: Ibrahim Capar, The University of Alabama, Box 870226,
Tuscaloosa, AL, United States of America,
1 - The Vehicle Routing Problem with Drones: A Worst-case Analysis
Xingyin Wang, University of Maryland, Mathematics department,
University of Maryland, College Park, MD, 20742, United States
of America, , Stefan Poikonen, Bruce Golden
We introduce the Vehicle Routing Problem with Drones (VRPD). A fleet of trucks
equipped with drones delivers packages to customers. Drones can be dispatched
from and picked up by the trucks at the depot or the customer locations. The
objective is to minimize the maximum duration of the routes. We compare VRPD
to the min-max Vehicle Routing Problem from a worst-case perspective and show
that the maximum savings from using the drones depends on the number and the
speed of the drones.
2 - Online and Open Vehicle Routing Problem with Split Delivery
Ibrahim Capar, The University of Alabama, Box 870226,
Tuscaloosa, AL, United States of America, ,
Burcu Keskin
We consider an online, open vehicle routing problem with split deliveries. This
type of problem is usual for companies that use common carriers with TL, LTL, or
container services. We develop an integer programming model and propose a
reduction technique to solve real life problem with commercial software. We
investigate the effect of lead time on cost and outstanding orders and explore
different policies to minimize total cost. We show more than eight percent savings
compared to the literature.
3 - Distributionally Robust Adaptive Vehicle Routing
Arthur Flajolet, MIT, Operations Research Center,
77 Massachusetts Avenue, Bldg. E40-149, Cambridge, MA,
02139, United States of America, Patrick Jaillet,
Sebastien Blandin
We consider an adaptive solution to the vehicle routing problem with stochastic
travel times with the objective of minimizing a risk function of the lateness. To
mitigate the impact of the lack of information on the travel times, we develop a
distributionally robust dynamic programming formulation for risk-averse travelers
and illustrate the practicality of the approach with field data from the Singapore
road network.
4 - A Metaheuristic for the Electric Vehicle Routing Problem with
Recharging Stations and Time Windows
Site Wang, Graduate Student, Clemson University, 854
Issaqueena Trail, APT908, Central, SC, 29630, United States of
America, Eric Huang, Scott Mason
In this study, we consider electric vehicles and recharging stations in the vehicle
routing problem with time windows. We examine two objectives for this problem,
separately and in concert, to provide insights for the location-routing problem
with time windows. Due to the problem’s complexity, we demonstrate the
efficacy of our two-phase metaheuristic that combines variable neighborhood
search and Tabu search for practical-sized problems.
TB68
68-Room 201B, CC
TSL Invited Cluster Keynote Address
Sponsor: Transportation, Science and Logistics
Sponsored Session
Chair: Irina Dolinskaya, Northwestern University, 2145 Sheridan Road,
Evanston, IL, 60208, United States of America,
1 - Stochastic Vehicle Routing: An Overview and Some
Research Directions
Michel Gendreau, Full Professor, École Polytechnique de
Montréal, P.O. Box 6128, Station Centre-ville, Montreal, QC, H3C
3J7, Canada,
While Vehicle Routing Problems have now been studied extensively for more
than 50 years, those in which some parameters are uncertain at the time where
the routes are made have received significantly less attention, in spite of the fact
that there are many real-life settings where key parameters are not known with
certainty. In this talk, we will examine the main classes of Stochastic Vehicle
Routing Problems: problems with stochastic demands, stochastic customers, and
stochastic service or travel times. We will emphasize the main approaches for
modeling and tackling uncertainty: a priori models, a posteriori approaches,
and chance-constrained models. The end of the talk will devoted to a brief
presentation of some interesting research directions in this area.
TB69
69-Room 201C, CC
Joint Session TSL/Public Sector: Health-care,
Education, and Emergency Applications of Logistics
Sponsor: Transportation, Science and Logistics
Sponsored Session
Chair: Sung Hoon Chung, Binghamton University, P.O. Box 6000,
Binghamton, NY, United States of America,
1 - Public Transportation Planning for Mass-Scale Evacuations
Rahul Swamy, Graduate Research Assistant, University at Buffalo
(SUNY), 412 Bell Hall, Buffalo, NY, Jee Eun Kang, Rajan Batta
This research provides a public transportation planning strategy in an urban
setting for evacuating population groups to safe locations before a mass-scale
disaster. Under the objective of maximizing the number of evacuees, the proposed
model first identifies pickup locations and then constructs special type of routing
to serve a time-varying demand.
2 - Minimizing the Cost of Routing Blood Collection Vehicles
Okan Orsan Ozener, Ozyegin University, Cekmekoy, Istanbul,
Turkey,
We study the routing of blood collection vehicles to minimize the total routing
costs. Donated blood has to be processed within a certain amount of time. We
analyze the routing decisions and propose an integrated framework to minimize
the total cost while collecting a pre-specified number of donations.
3 - A Heuristic for School Bus Routing of Special-education Students
Hernan Caceres, SUNY Buffalo, 342 Bell Hall, Buffalo, NY, United
States of America, , Rajan Batta, Qing He
The problem of routing special-education students differs in many aspects with
that of routing regular students. A bus can be configured to also support
wheelchairs, students may be served differently depending on their disability, and
they need to be picked up and dropped off in their homes. In our study we
modeled a mixed integer program that accounts for these and other
characteristics. We use column generation to find approximated solutions for real
and benchmark instances.
4 - Disaster Relief Routing under Uncertainty: A Robust
Optimization Approach
Sung Hoon Chung, Binghamton University, P.O. Box 6000,
Binghamton, NY, United States of America,
, Yinglei Li
We explicitly consider uncertainty in travel times when planning vehicle routes
for delivering critical supplies to the affected population in need in the aftermath
of a large disaster. In particular, we propose the robust optimization approach to
minimize the impact of uncertainty and eventually to achieve enhanced resilience
in the aftermath of disasters. We also explore several numerical methods and
algorithms.
TB69