TECHNICAL PROGRAM

Information Systems & Technology Conference

The second INFORMS Joint Conference on Information Systems & Technology, IS&T, will be held in conjunction with the INFORMS San Diego Spring 1997 Meeting. The conference is sponsored by the College of Information Systems and the College on Artificial Intelligence.

This conference requires an additional conference registration fee as indicated on the registration form. Attendees will be able to participate in all activities and sessions of the INFORMS San Diego Meeting.

The conference will provide a forum for all groups related to information systems and information technology to present and discuss their views, issues and research results.

Each day will begin with a keynote speaker. Andrew Whinston will speak on "Electronic Commerce" and Robert Hecht-Nielsen will give a presentation entitled, "Context Vectors: A Practical Approach for Automatically and Economically Acquiring Trillions of Real-World Factoids." Additionally, there will be two panels, one tutorial session and eight paper sessions. Each attendee will receive a proceedings containing the reviewed and accepted papers and extended abstracts.

See the homepage at www.cba.ufl.edu/dis/istc/.

Invited Tutorials

SA18 Health Care Information Systems
Rema Padman, Carnegie Mellon University

The explosive advances in medical and information technology in recent years combined with the current climate for health care reform have created many challenges in developing, adapting, and integrating information systems for cost-effective health care administration and delivery. This tutorial will present an overview of the major information systems methodologies and approaches in the delivery of modern health care systems. In particular, specific challenges, potential solutions, and linkages in the areas of clinical and administrative decision support, and Internet based applications will be highlighted.

SB18 Fair Division: From Cake-Cutting to Dispute Resolution
Steven J. Brams, NYU

Cutting a cake, dividing up property in an estate, determining the borders in an international dispute - these and other problems will be used to illustrate how constructive procedures can be applied to allocating goods, and deciding who wins on what issues, that satisfy such properties as envy-freeness, equitability, and Pareto-optimality.

SC18 Entropy Optimization and Mathematical Programming
S.-C. Fang, North Carolina State University; J.R. Rajasekera, International University of Japan; H.-S.J. Tsao, University of California

Although the word "entropy" has been around since 1865 in the literature of physics, it gained wider publicity with the work of Shannon's Information Theory in 1948. Later, Jaynes proposed the principle of maximum entropy and inspired its application to many areas, including management, finance, transportation, urban planning, OR and statistics.

SD18 Research Issues on Supply Contracts
Christopher S. Tang, UCLA

To compete in a global market, many manufacturers have outsourced some of the components (or manufacturing operations) to various suppliers (or contract manufacturers). In many instances, the manufacturers pressure suppliers to lower the cost or to increase delivery flexibility. To relieve the pressure on the supplier, it is common for the supplier and the manufacturer to negotiate certain characteristics (in terms of order quantities, delivery lead time, etc.) of the supply contracts. This tutorial presents some of the issues arising from different types of supply contracts. In addition, we review various models that have been examined in the literature.

SE18 Selected Developments in Supply Chain Management
Evan L. Porteus, Stanford University

Supply chain management encompasses not only traditional operational management of multi-echelon production, inventory, and distribution systems, it includes the design of such systems, including the coordinating mechanisms and technologies that facilitate the flows between distinct people, locations, and organizations that comprise these systems. The area is too broad to warrant attempting a comprehensive tutorial, so this presentation will limit itself to topics of particular interest to the speaker.

MA18 Nonlinear Programming
Leon Lasdon, University of Texas

This tutorial will survey recent advances in NLP software, modeling languages, and applications. Software includes GRG and SQP solvers, and recent advances in interior point and SLP algorithms. Both algebraic languages and spreadsheets solvers are discussed. In applications, we consider financial models and new work in the optimization of simulations.

MB18 Applied Conjugate Duality
Thomas R. Jefferson, Sultan Qaboos University

This presentation is intended for people interested in applying conjugate duality to gain insight into OR applications. Conjugate duality has its roots in mathematics; however it has been found to be valuable in understanding problems which can be modeled as convex programs. Initial applications were engineering oriented as nonlinear engineering models are quite common. To improve their accuracy, business models are increasingly incorporating nonlinear relationships. Here we explore the application of conjugate duality to a wide variety of models in the framework of a relatively easy methodology for its application.

MC18 Geometric Programming
K.O. Kortanek, University of Iowa

Geometric programming as a next level of extension LP owes its origins to the arithmetic-geometric mean inequality. During the last 35 years, manifest applications have occurred in many fields, including engineering design, reliability, operations (project management and lot sizing), economics and marketing, statistical inference, entropy, and telecommunications. Recent advances in interior point methods have led to efficient algorithms for solving both primal and dual (polynomial) GP - problems having enormous degrees of difficulty, simultaneously. A main goal of this tutorial is to demonstrate the wide applicability of GP and to increase the skills of the participants for recognizing opportunities for modeling otherwise intractable nonlinear problems as GPs. A review of the basic features of the new GP algorithms will be given together with recently developed (GP) large-scale problems which are becoming additions to libraries of GP test problems in several countries. Finally, recent approaches for numerically treating the nonconvex "signomial" GP or "reversed" GP will be surveyed, with a look towards the efficient use of recent LP and GP solvers in a necessarily global optimization approach for this class of problem, including the more familiar branch & bound methods.

MD18 Operations Strategy in Service Management
Uday S. Karmarkar, UCLA

Just as with service operations, the special characteristics of services require novel approaches to the analysis of service competition. The absence of a tangible product means that traditional quantity based models of demand and supply, or of value and cost do not apply very well. Furthermore, the lack of a portable product naturally affects the structure of service chains. We present issues in the modeling of service competition and the implications for strategy development. The special features of information intensive industries, such as publishing, financial services and education, are discussed. The topics addressed include competitive models, operations and marketing integration, service chains, service design and location.

TA18 Service Operations Management: An Agenda for Normative and Empirical Analysis
Patrick T. Harker, University of Pennsylvania

The service sector is not only the largest segment of all developed economies, but also consumes over 85% of information technology investment every year. As such, this segment provides tremendous opportunities for academic research and the application of OR/MS methodologies. This tutorial will review the state of the art in the analysis of service operations in general, will provide a detailed analysis of these method to financial services, and will provide a framework for the emerging discipline of service operations management.

TB18 Bucket Brigades: An Example of Self-Organizing Logistic Systems
John J. Bartholdi, III, Georgia Institute of Technology; Donald D. Eisenstein, University of Chicago

Social insects such as ants or bees operate logistics systems that are highly effective even without blueprint or management. Instead, global coordination emerges spontaneously, through the multiple interactions of many simple components. In a similar way, when workers on a flow line are organized into "bucket brigades," they can function as a self-organizing system that spontaneously achieves its own optimum configuration. We report on models and case studies in manufacturing and distribution.

TC18 Fractional Programming, Generalized Convexity & Generalized Monotonicity
Siegfried Schaible, University of California

In many models of management and economics, the rigid assumption of convexity can be relaxed to various types of generalized convexity without losing properties important for solving such models, for example, single- and multi-ratio fractional programs. More recently, the rigid assumption of monotonicity has been replaced by different kinds of generalized monotonicity, e.g., in complementary problems, variational inequality problems and the more general equilibrium problems in the sense of Blum Oettli. We survey concepts and uses of generalized convex functions and generalized monotone maps.

TD18 Robust Discrete Optimization and Its Operations Management Applications
Panos Kouvelis, Washington University; Gang Yu, University of Texas

This tutorial deals with decision making in environments of significant data uncertainty, with particular emphasis on operations and production management applications. For such environments, we suggest the use of the robustness approach to decision making, which assumes inadequate knowledge of the decision maker about the random state of nature and develop a decision that hedges against the worst contingency that may arise. Robust discrete optimization is a comprehensive mathematical programming framework for robust decision making. Our framework applies minimax regret criteria to differentiate the performance of the various solutions over the given set of realizable scenarios and it is mostly developed for models with discrete decision variables using state of the art convex and combinatorial optimization techniques. We demonstrate the applicability of the framework to a variety of decision making environments such as resource allocation, scheduling, production planning, location, inventory, layout planning, and well known optimization models (assignment, knapsack, shortest paths, spanning trees, network design).

TE18 Tabu Search for Discrete, Nonlinear and Stochastic Optimization
Fred Glover , James P. Kelly, Manuel Laguna, University of Colorado

The hallmark of tabu search is an integrated collection of search strategies based on creating and exploiting adaptive memory structures. The flexibility of adaptive memory structures has long been emphasized as the key to the success of TS approaches. Such memory contrasts with the rigid memory structures of classic OR and artificial intelligence procedures such as branch and bound and its various tree search incarnations, and also contrasts with the "memoryless" designs of approaches such as multistart methods, simulated annealing and genetic algorithms. Enhanced forms of adaptive memory strategies in tabu search are yielding new "records" for solving optimization problems from a wide range of applications, including resource planning, telecommunications, VLSI design, financial analysis, scheduling, seismic inversion, space planning, molecular engineering, facility location, neural network design and training, graph partitioning, transport planning, pattern classification, and general nonlinear and combinatorial problems with stochastic parameters. We review the basic principles of tabu search and survey its recent applications, and provide computer demonstrations of its performance. Included is a new software demonstration of a "proto-generic" tabus search procedure.

WA18 Constraint Programming
Carol Tretkoff, Ken McAloon, Brooklyn College

Constraint programming supports constraints as first-class objects in programming systems. Those who attend will learn how to use constraint programming to build hybrid discrete and continuous models to solve problems at the AI/OR interface. The problem solving methods presented and demonstrated will include constrained quadratic regression, the injury method, branching on the dual side, least discrepancy search and randomized shuffle algorithms. Available finite domain constraint libraries and the issue of libraries vs. languages will be discussed. The 2LP language, "Linear Programming & Logic Programming," will be used; it is a small system with C-like syntax easy to pick up.

WB18 Structural Equation Modeling Using LISREL
George Marcoulides, California State University

Structural equation modeling (SEM) is concerned with testing complex models for structure of functional relationships between observed variables and latent variables. The functional relationships are described by parameters that indicate the magnitude of the effect that independent variables have on dependent variables. As implemented in most computer packages, SEM includes as special cases such procedures as confirmatory factor analysis, multiple regression, path analysis, models for time-dependent data, recursive and non-recursive models for cross-sectional and longitudinal data, and covariance structure analysis. This tutorial will introduce SEM techniques via the LISREL (Version 8) computer program.

Plant Tours

Sony Manufacturing Plant, $41

Visit one of the largest TV plants in Southern California. The plant produces TVs for both domestic and foreign consumption. The tour will cover the steps in the manufacture of TV sets from the arrival of material at the receiving dock, through manufacturing, to the shipping department where they are sent to foreign and domestic markets. Buses depart Monday, May 5, at 1:00pm; tours will last approximately 2 hours.

Defense Distribution Depot (Naval Supply Depot), $41

Visit the Defense Distribution Depot which supplies military establishments in Southern California and Yuma, Arizona. The tour will take you through the depot's storage facilities and shipping docks. Attendees are always amazed at the magnitude of the operations required to keep the military facilities supplied. Buses depart Tuesday, May 6, at 1:00pm; tours will last for approximately 2 hours.

Reviewed Contributed Papers

The INFORMS Board has begun a review process which hopefully will enhance the quality of presentations. The Meetings Committee initiated a new class of papers known as "Reviewed Papers." All reviewed papers will be identified with an R in the program.

The purpose of the review process is to enhance the quality of the presentations rather than to review the papers for contribution to the literature or originality of ideas. Attention is paid to content, organization, presentation and legibility. Complete copies of all reviewed papers will be available at the session. The following contributed papers have been reviewed:

• "Towards Finding Global Representations of the Efficient Set in Multiple Objective Mathematical Programming" H.P. Benson, S. Sayin
• "Knowledge Acquisition & Presentation in a Student Model" Q. Chen, A. Kumar
• "Constructing Complex Scales for Evaluating Alternative Combinations of Multiattribute Items" C.-F. Chien, F. Sainfort
• "Computer-Based Tourism Information System: Need of Turkey" B. Egeli, M. Ozturan
• "Vulnerability Assessment of Hierarchies & Markets" G.N. Kenyon, A. Talalayevsky
• "Effect of External & Internal Learning Rate Differences on Manufacturing Improvement" B. Kim
• "Effects of Incentive & Probabilistic Management Audit on Profit Center Managers' Transfer Price Negotiation Task" S. Mahenthiran
• "Deterministic Chaos in the Capacity Expansion Race: A Study of the Airline Industry" R. Rao, Y. I. Song, S. Rajagopalan
• "Efficiency Analysis of Markets in Pacific Rim Countries" R. Singamsetti
• "Development & Use of a Dynamic Computable General Equilibrium Global Model in Evaluating Trade Reforms" A. Somwaru, X. Diao
• "Identification of Strategic Groups Based on Strategic Interactions: A Network-Analytic Approach" Y.I. Song

Special Sessions

• 26th Annual Franz Edelman Award for Achievement in OR/MS Competition Presentations

  Representing applications from fast food operations to railroad scheduling systems, 6 finalists will vie for the 1997 Franz Edelman Award for Achievement in Operations Research and the Management Sciences.

  Stephen Strauss, Chair of the 1997 competition, announced the following finalists: Hewlett Packard, Nortel, Pacific Gas & Electric Company, Sabre Decision Technologies, Taco Bell Corporation and the US Department of Energy.

  Finalist presentations for the 1997 competition will be given on Sunday, May 4, during the INFORMS San Diego meeting at the Town & Country Hotel. Those interested in the practice of OR/MS are encouraged to attend the day-long presentation session. The cost is $95 per person and includes lunch and a post-presentation reception.

  This is the 26th year that the prestigious $15,000 competition has been held. The award is jointly sponsored by INFORMS and CPMS, the Practice Section of INFORMS. The Edelman Award recognizes outstanding implemented work that has had a significant positive impact on the performance of the client organization. The top finalist receives a $10,000 first prize.

  The work to be presented by this year's finalists covers a wide range of operations research applications. Finalist information follows:

  Hewlett Packard - M. Burman; "The Use of Operations Research Techniques to Improve the Design of a Hewlett Packard Printer Production Line."

  Hewlett Packard planned to build a large automated manufacturing system for Ink Jet printers. Originally, they planned to use a flow line design with multiple sub-assembly cells of more than 100 processes separated by virtually no buffers. The resulting system throughput proved to be inadequate. Since the system was already being built, individual machines could not be changed without significant disruption to the product development cycle. It was decided that the best way to improve the throughput was to install limited buffers at strategic points. Within 1 week, recommendations were in place that promised to almost double the expected system throughput at a relatively low cost and with a minimum impact on the flow-time and WIP. This work led to a savings of several million dollars per month and was successfully applied to other projects within the division.
  

  Nortel - P.A. Brinkley, D. Carr, J. Folger, K. Haag, K. Liou, D. Stepto, K. Wang,: "Redefining Factory Information Technology: An OR-Driven Approach."

  A team of new graduate and experienced engineers was recruited to implement an enterprise information system for Nortel's new PCS1900 cellular equipment manufacturing operation. This system provides real-time access to production metrics relating to quality, inventory and cycle time, along with linked analysis tools providing real-time decision support. These tools, including a simulation environment, expert systems and statistical product design analysis system, are accessible to production workers, managers and engineers through the intranet using Netscape. In addition, inexpensive real-time access to factory information from the desktop eliminated costly delays resulting from gathering, analyzing and transferring data. Normally requiring costly time consuming development by programmers and MIS specialists, this approach of using OR specialists resulted in a complete implemented network and decision support system in less than 1 year. This marked a major shift from traditional shop floor systems deployment within Nortel and the industry in general, and illustrates an opportunity for OR to assume a leadership role in system implementation in manufacturing operations.
  

  Pacific Gas & Electric Company - C. Greif, R.B. Johnson, A.J. Svoboda, A. Vojdani, F. Zhuang: "Pacific Gas & Electric Company's Hydro-Thermal Optimization Model."

  Since 1992, PG&E Company's Hydro-Thermal Optimization system has been the primary decision support tool for the short-term scheduling of its generation resources. HTO is a significant asset to PG&E in helping system operators and energy traders adjust competitively, especially in light of the impending deregulation of the industry. The model development group has also been able to act as an internal consulting group, quickly incorporating new operating considerations. The benefits of using the HTO model have been estimated at $1 million per month, along with an estimated savings of $3 million per year in its specific application to the voluntary curtailment of qualifying facilities production during low energy cost periods.
  

  Sabre Decision Technologies - N. Ben-Kheder, J. Kintanar, C. Queille, W.K. Stripling: "Decision Support Scheduling Systems for SCNF."

  The national railroad of France, Societé Nationale des Chemins de Fer Français, and Sabre Decision Technologies teamed up to address the problem of train capacity allocation in SNCF's network of high-speed electric-powered Trains Grand Vitesse, which carry more than 50 million passengers per year among 140 cities in both France and Europe. Used to develop advance schedules and published timetables, RailPlus is composed of 5 modules: a workset manager, a profitability module, a feasibility module, a capacity allocation module and a routing module. The capacity allocation module utilizes a "subgradient" algorithm to solve an integer non-linear stochastic optimization problem, while the routing module was cited as being particularly robust. RailCap also uses a similar capacity allocation model to monitor the reservation activity for all trains and to add extra trains to the schedule when necessary. The implementation of the DSSs is credited with an overall profit increase of 3-5%, reductions in manpower and schedule development time and improvements in planning and scenario development.
  

  Taco Bell Corporation - J. Hueter, W. Swart: "An Integrated Labor Management System for Fast Food Operations."

  Following the introduction of the "value meal" in 1990, Taco Bell launched a major study to develop a labor management system in order to control labor costs. There were 3 model components to their analysis: a demand forecasting model, a simulation model to determine the appropriate staffing to meet customer demand and an optimization model to perform the staff scheduling function. Data are collected periodically to allow for updates in model parameters, as well as changes in the model structure. Labor savings of 1 hour per day per company-owned store were achieved, yielding a savings of more than $7.6 million per year.
  

  US Department of Energy - E. Schweitzer, D. von Winterfeldt: "An Assessment of Tritium Supply Alternatives in Support of the US Nuclear Weapons Stockpile."

  Nuclear weapons need to be serviced and maintained, and in particular, they require the periodic replacement of tritium. Since there currently exists no tritium production facility in the US, tritium supplies will fall below the required reserve level in 2011. To decide how to fill this projected gap, the Department of Energy conducted a major assessment of 10 tritium technology alternatives, including building a new reactor, purchasing commercial reactor(s) and building an accelerator. Each supply alternative involved risks of schedule overruns, production shortfalls, cost overruns and environmental impacts. These risks were analyzed using formal probability elicitations, event tree analyses and Monte Carlo simulations. A dynamic production simulation was developed that combined the results of the schedule and production risk analyses to predict the production of tritium for each alternative over a period of 40 years. The analysis formed the technical basis for the decision for the Secretary of Energy to pursue both the commercial reactor options and the accelerator option for producing tritium.



• Edelman Award Presentation

  The winners of the 26th Annual Franz Edelman Award for Achievement in OR/MS Competition will be announced on Tuesday, May 6, 11:30am - 12noon in the San Diego Room. Don't miss this prestigious award as it is presented to honor the best implementation of operations research and management science by the six noted finalists.

• Navigating an INFORMS Meeting

  When you look at the meeting program, do you feel confused and overwhelmed? With enough time, do you think you can probably find your way to the right session or do you maybe think it;s just better to stick with one track and sit it out? What about all the non-technical program opportunities and special events?

  What is valuable to you and how do you find it? This short workshop will help you understand the structure of the INFORMS meeting and develop your personal compass to help you navigate the meeting and maximize the return on your registration fee. We will help you find the technical papers, tutorials, workshops, subdivision meetings, receptions, parties, business meetings, free food, exhibits, jobs, wine and cheese, and people. Whether you are a new member or an experineced INFORMer, wou will learn something new about the meeting. The workshop will be held on Sunday, May 4, 2:45 - 4:15pm in Le Sommet.

• New Member Welcome & Workshop

  Are you interested in finding out more about INFORMS? Are you new to INFORMS? Do you know about our many journals? How about our meetings and networking opportunities? Do you know about our individual member benefits such as life, disability, and health insurance, credit card or job placement services? Do you know how to get to INFORMS Online and your virtual INSTITUTE? Do you want to know more about how to get involved in the INstitute? Do you know about the chapters in your area, or the many sections and colleges that focus on specific methodological or application interests? This workshop is directed to new members in order to give you a chance to meet some INFORMS leaders, to learn more about the Institute, and to get answers to all your questions about the Institute. It is also a good way to get a discount coupon for many of the Insittute's products. The workshop will be on Sunday, May 4, 1:00 - 2:30pm in Le Sommet.