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INFORMS Philadelphia – 2015

198

2 - Distributionally Robust Stochastic Optimization using

Divergences- A Data Driven Strategy

Anand Vidyashankar, Associate Professor, George Mason

University, Department of Statistics, Volgeneau School of

Engineering, Fairfax, VA, 22030, United States of America,

avidyash@gmu.edu

, Jie Xu

We propose a new paradigm for data-driven distributionally robust stochastic

optimization (DRSO). This paradigm integrates existing approaches to decision

making under uncertainty with robust and efficient statistical procedures.

Specifically, it extends the scope of DRSO by centering the ambiguity sets on

density estimates neighborhoods in the space of probability densities. The

proposed approaches are transparent, theoretically justified, and accessible to

researchers and decision makers.

3 - Some Statistical Perspectives on Optimization under

Parameter Uncertainty

Henry Lam, Assistant Professor, University of Michigan, 1205

Beal Ave., Ann Arbor, MI, 48109, United States of America,

khlam@umich.edu,

Jeff Hong

We consider approaches to improve the quality of solutions for optimizations

under parameter uncertainty, in the case of limited data. We analyze two

computationally tractable methods: bootstrap aggregation, or bagging, and Bayes

estimator in the decision-theoretic framework. Both are simulation-based

schemes that aim to improve the distributional behavior of the optimality gap by

reducing its frequency of hitting large values.

4 - Simulation Optimization When Facing Input Uncertainty

Enlu Zhou, Assistant Professor, Georgia Institute of Technology,

755 Ferst Drive, NW, Atlanta, GA, United States of America,

enlu.zhou@isye.gatech.edu,

Xie Wei

This talk makes an attempt at the question of what is a good formulation for

simulation optimization when there is input uncertainty. We propose a risk

formulation of simulation optimization that tries to balance the trade-off between

optimizing under the estimated input model and hedging against the risk brought

by input uncertainty.

MB77

77-Room 300, CC

Supply Chain Management VI

Contributed Session

Chair: Bisheng Du, Assistant Professor, Ningbo University,

818 Fenghua Road, Ningbo, China,

dubisheng@nbu.edu.cn

1 - Supplier Development Investments under Competition

Tarun Jain, IIM Bangalore, FPM Office, IIM Bangalore,

Banerghatta R, Bangalore, India,

tarun.jain@iimb.ernet.in

,

Jishnu Hazra

We model a case, where a buyer is evaluating a new supplier. The buyer allocates

some capacity to the incumbent supplier and makes supplier development

investments in the entrant supplier. Both incumbent and entrant supplier also

exerts improvement investments. We find the optimal investments strategy of

these players and the optimal capacity allocation strategy of the buyer.

2 - Analysis and Design of Retail Backrooms and its Impact on

Supply Chain

Lita Das, Student, MIT, 77 Massachusetts Avenue, E40-286,

Cambridge, MA, 02139, United States of America,

litadas@mit.edu

, Edgar Blanco

Backroom space management and supply chain operations are closely linked. We

propose a model to optimally manage backroom space and demonstrate the

impact on retail supply chain planning and design.

3 - An Evaluation of the Progressive Formulation (PF) through the

Modeling of the PCSA

Daniel Mota, Researcher, MIT, Rua Jose de Magalhaes 373, Vila

Clementino, Sao Paulo, SP, 04026, Brazil,

danmota@mit.edu,

Roberto Perez-franco

Progressive Formulation (PF), an ad-hoc approach recently proposed for

formulating a supply chain strategy, has shown potential in applied projects but

has never been objectively evaluated. This paper attempts a first evaluation of the

merits of the PF approach, by modeling PF as a greedy algorithm and comparing

its results against an optimal solution for the same data set. Results are compared

in terms of the quality of the solution generated and the amount of information

needed to achieve it.

4 - Capacity Planning over a Finite Time Horizon with Dual Contracts:

An Optimization Approach

Ramya Ravi, Student, Indian Institute of Technology, Madras,

Chennai, 600036, India,

ramya.tcemdu@gmail.com

,

Haritha Thirrumalai, Rajendran Chandrasekharan,

Vivekanandan Srinivasan

We consider a supply chain with multiple products manufactured using processes

outsourced to suppliers by the manufacturer. Capacity planning contracts

(i.e.,fixed charge and option, with setup/order costs) are considered. We present

an algorithm to determine the capacity investments, considering the total supply

chain profit over a finite time horizon.

5 - Optimal Fulfillment Decisions in a Capacitated Online Retailing

System with Different Leadtimes

Bisheng Du, Assistant Professor, Ningbo University,

818 Fenghua Road, Ningbo, China,

dubisheng@nbu.edu.cn

Online retailers offer more options, like flexible delivery, pricing, etc. We consider

an inventory system where customers may have different lead-times under the

retailer’s capacity. The retailer has a primary warehouse and many regional

warehouses. The regional warehouses fulfill the customers’ orders by on-hand

inventory, or the primary warehouse will fulfill orders with longer time. Our

intension is to analyze the performance of the capacitated retailing system under

the multistage setting.

MB78

78-Room 301, CC

Shipping and Transportation for Supply Chains

Contributed Session

Chair: Sherif Masoud, Operations Research Analyst, RockTenn, 3950

Shackleford Rd., Duluth, United States of America,

smasoudphd@gmail.com

1 - Port Logistics and the Voice of the Customer

Richard Monroe, Visiting Assoc Prof, Longwood Univ, College of

Business and Econ, 201 High Street, Farmville, VA, 23120,

United States of America,

rickmon53@gmail.com

Customers are key stakeholders for logistics services through the various modes

which include seaports, trucking, rail and inland ports. Primary customers such as

manufacturers and retailers are highly dependent on the smooth flow of freight

through the logistics system. Customer expectations for logistics services have

received limited attention in previous research. This paper will utilize a

combination of approaches to explore the voice of the customer in the port

logistics setting.

2 - A New Formulation for the Cyclic Inventory Routing Problem and

the Solution Method

Zhe Liang, Professor, Tongji University, No. 1239, Siping Road,

Shanghai, 200092, China,

liangzhe@tongji.edu.cn,

W. Art Chaovalitwongse

We study a cyclic inventory routing problem (IRP). The traditional exact methods

for IRP use an arc-based model, in which a variable represents a possible vehicle

flow between a pair of customers. We develop a Dantzig-Wolfe reformulation for

the arc-based model. To solve the problem efficiently, we develop a set of valid

inequalities and a column generation algorithm. Computational results show that

the new model can obtain near optimal solutions to very large test cases in a

reasonable time.

3 - Robust Supply Chain System under Yield Uncertainty

Samir Alsobhi, PhD Candidate, Wichita State University, 11328 E

Pine Meadow Ct, Wichita, KS, 67206, United States of America,

samiralsobhi@gmail.com

, Krishna Krishnan

Products are often damaged in transit.These damages are stochastic in

nature.To

minimize the impact of damage,the selection of routes should consider not only

the expected damage but also the variability of

damage.In

this research,the first

model is of the supply chain network in order to minimize total cost,which

consists of product cost and transportation cost while considering multiple routes

and

products.In

the second model,the concept of robust design has been applied

to minimize damage.

4 - A Floating Price Contract for the Ocean Freight Industry

Ruina Yang, Xi’an Jiaotong University, No. 28 West Xianning

Road, Xi’an, China,

rnyang@mail.xjtu.edu.cn

We propose a floating price policy to address the shipper default issue. Specifically,

the shipper has to make a tradeoff between not fulfilling all committed capacity to

secure a lower spot price in the low season and purchasing the capacity at a

higher floated price in the high season. The results reveal that the non-capacity

commitment contract serves both parties’ best interests under a tight-capacity

market, while the floating price contract is the most effective in an over-capacity

market.

MB77