Department of Information Systems
Stern School of Business
New York University
email: hlucas@stern.nyu.edu

ABSTRACT: Reengineering of business process redesign has become very popular. This paper presents a framework for comparing and evaluating reengineering efforts. The framework is applied to a case study of the reengineering of the securities processing function at Merrill Lynch. The paper compares the old and new process at Merrill. The new process features image capture, character recognition and extensive redesign. The reengineering effort has had a substantial payback for the firm.

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Henry C. Lucas, Jr.
Department of Information Systems
Leonard N. Stern School of Business
New York University
email: hlucas@stern.nyu.edu

Margrethe Olson
DMR Group
Victoria, Australia

ABSTRACT: This paper argues that information technology can have a significant impact on organizational flexibility. Information technology (IT) contributes to flexibility by 1) changing the nature of organization boundaries and the time when work occurs 2) altering the nature and pace of work and 3) helping firms respond to changing market conditions. But, there are also aspects of technology which can decrease flexibility, and there may be second-order impacts of flexibility that are not easily predicted. Examples to illustrate the impact of information technology on two industries and three companies are presented. The paper concludes that management should consider the use of information technology to increase flexibility and suggests strategies for implementing flexible systems.

Keywords: Organizational flexibility, impact of information technology, implementation, second order effects.

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Department of Information Systems
Stern School of Business
New York University
email: hlucas@stern.nyu.edu

ABSTRACT: This paper introduces a set of information technology variables which can be used in designing organizations. We first look at traditional design variables and then present a series of options enabled by modern information technology. We use these IT design variables to describe four prototypical organizations in which are beginning to appear in the work place: virtual, negotiated, traditional and vertically integrated. It is argued that an organization designer must also consider how structure and technology influence job tasks and people in order to be successful. The paper discusses potential implementation difficulties, particularly in motivating traditional organizations to take advantage of IT design variables. The paper concludes that the design of information technology and the design of organizations is largely becoming the same task.

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Department of Information Systems
Stern School of Business
New York University
email: tisakowi@stern.nyu.edu

ABSTRACT: Software reuse in the presence of a repository and object-based CASE tool is likely to be "biased". Prior research has shown that a developer will be: (1) most likely to reuse her own objects; (2) somewhat less likely to reuse objects developed by her project team members; and, (3) even less likely to reuse objects stored in the repository, but developed elsewhere in the corporation. These biases can result in sub-optimal levels of software reuse. In the presence of such biases it is appropriate to deploy that support the search for software reuse, so that developers find it easier to reuse software objects authored by developers other than themselves or project team members. However, the tools that are chosen or created for this purpose must adequately treat the technical and cognitive fundamentals of the problem for individual developers, and recognize the organizational and perspectives of a firm that wishes to maximize the business value of its software development activities. In this paper we present a two-stage descriptive model that represents the search process for reusable objects. We evaluate appropriate technologies, propose a technical solution to the problem of searching for reusable objects, and demonstrate its feasibility via a prototype implementation. The technical tool combines an automated classifier and a hypertext system. We describe an architecture to automatically create hypertext networks based on the classification schema. We illustrate our architecture using a classification of software objects obtained through structured interviews with software developers.

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Department of Information Systems
Stern School of Business
New York University
e-mail: tisakowi@stern.nyu.edu

Rachna Kumar (now at California State University at San Marcos)
College of Business Administration
University of Texas at Austin

Dani Zweig
Department of Administrative Sciences
U.S. Naval Postgraduate School

ABSTRACT: The past few years have seen the introduction of repository-based computer aided software engineering (CASE) tools which may finally enable us to develop software which is reliable and affordable. With the new tools come new challenges for management: Repository-based CASE changes software development to such an extent that traditional approaches to estimation, performance, and productivity assessment may no longer suffice - if they ever did. Fortunately, the same tools enable us to carry out better, more cost-effective and more timely measurement and control than was previously possible.

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Mark Ginsburg
Department of Information Systems
Stern School of Business
New York University
e-mail: mginsbur@stern.nyu.edu

Steven O. Kimbrough
University of Pennsylvania

Bruce W. Weber
Department of Information Systems
Stern School of Business
New York University
e-mail: bweber@stern.nyu.edu

ABSTRACT: The increased use of network communications within industries, and among firms, suppliers, and customers, is focusing greater attention on the methods and standards for interorganizational communications. In the securities industry, the settlement and clearing of trades depends on numerous messages to be sent and received by several organizations. Using the principles of Formal Languages for Business Communication (FLBC), we develop a message representation that is flexible and self describing, and show how defeasible reasoning applied to settlement messages could handle problem trades. This application of FLBC offers advantages through machine-to-machine error reconcilement, integration with other market communications systems, and robustness to changes in securities design and regulation.

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Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

ABSTRACT: This paper describes a Query-Driven Simulation (QDS) approach to asking questions about outcomes of business processes. In this approach a user issues a query about outcomes of simulation runs and, based on the query asked, appropriate simulations are launched and the answer to the query is determined from the outcomes of these simulations. It is argued that Query-Driven Simulations provide a more declarative, flexible, and interactive approach to asking questions about simulation outcomes than the traditional approaches of letting the end-users run simulations and gather statistics about simulation outcomes. The paper also presents a new simulation system development life cycle based on the QDS approach.

Keywords: Query-driven simulations, discrete-event simulations, temporal databases, query languages.

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Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

ABSTRACT: When decision makers want to know outcomes of business processes in their organizations, they often use simulations to do this. This paper describes how a new Query-Driven Simulation (QDS) approach can be used by decision makers to obtain information about future outcomes of business processes in a more decorative, flexible, and interactive way than the traditional approach of running simulations and then gathering statistics about simulation outcomes. The paper also describes the types of questions decision makers ask about outcomes of business processes and studies how easy it is to express these questions in terms of an SQL-like query language SimQL designed for Query-Driven Simulations. It also identifies the types of applications that are especially well-suited for QDS. Finally, the paper describes the Query-Driven Simulation Modeling Lifecycle and how QDS provides a feedback loop in the model development process.

Keywords: Decision support, query-driven simulations, discrete-event simulations, databases, query languages, modeling lifecycle.

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Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

ABSTRACT: A Query-Driven Simulation system Cassandra+ is described. It allows end-users to ask queries about outcomes of running simulation models written various simulation languages. The architecture of Cassandra+, its query language SimQL, and the implementation of the system are described. It is argued that Query-Driven Simulations provide a more declarative, flexible, and interactive approach to asking questions about simulation outcomes than the traditional approaches of letting the end-users run simulations and gather statistics on the trace files being produced.

Keywords: Decision support, query-driven simulation, discrete-event simulations, temporal databases, temporal query languages.

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Department of Information Systems
Stern School of Business
New York University
e-mail: akambil@stern.nyu.edu, jturner@stern.nyu.edu

ABSTRACT: Outsourcing provides new options for managers to govern and provide information technology infrastructures and services to firm. In this exploratory paper we identify ways in which managers may use outsourcing tactically to better align business and information technology strategies. Specifically we consider how selective outsourcing enables better alignment of incentives, business revenues and IT infrastructure costs, and organizational intent with capability. We also consider the role of outsourcing as a critical incident in supporting major organizational transformations, and enabling new models of IT organization to cope with technological discontinuities.

Based on our analysis we propose a series of testable propositions on outsourcing. The contributions of this paper includes refinement of the business strategy and information technology alignment frameworks, to consider interdependence between projects, product life cycle effects, and technology transfer.

Finally, the paper highlights new directions for outsourcing research focusing more on the effects of outsourcing on the IT organization, and the processes of internal technology development, and the transfer of technologies between organizations.

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Department of Information Systems
Stern School of Business
New York University
e-mail: teisakowi@stern.nyu.edu, estohr@stern.nyu.edu

ABSTRACT: We describe a step-by-step methodology for the design and construction of hypermedia applications and illustrate our approach using a small application. The Relationship Management Design (RMD) methodology begins with a data model of the application domain and proceeds through the design of the hypertext network, user interface and run-time dynamics finally concluding with the construction and testing of the target hypermedia system. Our ultimate objective is to use the RMD approach as the basis for the construction of computerized tools to support the design and development of hypermedia applications.

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Robert J. Kauffman (now at University of Minnesota)e
Stern School of Business
New York University
e-mail: rkauffman@csom.umn.edu

Charles Wright
Financial/Brokerage Systems
Seer Technologies

Dani Zweig
U.S. Naval Post Graduate School

ABSTRACT: Measurement of software development productivity is needed in order to control software costs, but it is discouragingly labor-intensive and expensive. Computer aided software engineering (Case) technologies -- especially repository-based, integrated CASE -- have the potential to support the automation of this measurement. In this paper, we discuss the development of automated analyzers for function point and software reuse measurement for object-based CASE. Both analyzers take advantage of the existence of a representation of the application system that is stored within an object repository, and that contains the necessary information about the application system. We also discuss metrics for software reuse measurement, including reuse leverage, reuse value and reuse classification, that are motivated by managerial requirements and the efforts, within industry and the IEEE, to standardize measurement. The functionality and analytical capabilities of state-of-the-art automated software metrics analyzers are illustrated in the context of an investment banking industry application, that is similar to systems deployed at the New York City-based investment bank where these tools were developed and tested.

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Department of Information Systems
Stern School of Business
New York University
e-mail: kduliba@stern.nyu.edu, rkauffman@stern.nyu.edu

ABSTRACT: This chapter presents an edited transcript of an interview held in August 1993 with Brian Slater, a vice-president in the Global Bank at Chemical Bank. Slater is responsible for the firm's U.S.-based trading and global risk management systems. The interview was conducted in the context of Project 1990's -- the U.S. Council for International Banking's Study on Information Technology Investment and International Banking Performance. The purpose of the discussion was to develop background information on the issues the bank's senior management team faced in merging the trading and treasury functions of Chemical Bank and Manufacturer's Hanover Trust. The new Global Bank faces challenges in the areas of global risk management, cost effective delivery of information technology-based products, trading infrastructure application functionality gaps, and human resource management that...

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Robert J. Kauffman (now at University of Minnesota)
Department of Information Systems
Stern School of Business
New York University
e-mail: rkauffman@csom.umn.edu

ABSTRACT: A unique data set is used to examine the determinants of membership in the Yankee 24 shared Automated Teller Machine (ATM) network. Recent work suggests that the presence of demand side network externalities influences the decision to join a network. A model is constructed in which characteristics of the bank and the market affect the value of the network externality. A hazard function is estimated to gauge the strength of these various influences in determining network membership. The results accord with the theoretical model and show that the size of the existing network and the number of expected locations in the network, proxied by the number of branches in a bank's market, are both strong influences on network adoption that are external to the individual bank.

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Robert J. Kauffman (now at University of Minnesota)
Department of Information Systems
Stern School of Business
New York University
e-mail: rkauffman@csom.umn.edu

ABSTRACT: Contact Professor Kauffman at the University of Minnesota

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Department of Information Systems
Stern School of Business
New York University
e-mail: vdhar@stern.nyu.edu, kduliba@stern.nyu.edu, rkauffman@csom.umn.edu

April 6, 1993

ABSTRACT: Maximizing business value of investments in hardware, software and telecommunications technologies that occur in the trading and treasury operations of an international bank requires senior management to evaluate the extent to which the technology infrastructure enables the bank to perform a number of key functions. These include: formulating effective trading strategies, pricing financial instruments accurately and rapidly, being able to respond to changing market conditions, processing transactions cost-effectively, resolving inquires quickly, and moving to support emerging corporate treasury products. After a decade of rapid growth in investment levels, senior managers new emphasize refining, rationalizing and integrating trading and treasury technology architectures to support improved global financial risk management, better capital utilization, and higher transaction volumes. This chapter examines how senior managers can accomplish these goals by re-engineering pre-trade, trade execution and post-trade business processes. It presents a framework that utilizes basic concepts from management science and microeconomics to illustrate the variety of impacts that re-engineering can have on improving firm revenues and controlling or reducing costs. It also presents a series of managerial recommendations based on the framework.

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Robert J. Kauffman (now at University of Minnesota)
e-mail: rkauffman@csom.umn.edu

Rob R. Weitz
Department of Information Systems
Stern School of Business
New York University
ABSTRACT: Under circumstances where data quality may vary (due to inaccuracies of lack of timeliness, for example), knowledge about the potential performance of alternate predictive models can help a decision maker to design a business value-maximizing information system. This paper examines a real-world example from the field of finance to illustrate a comparison of alternative modeling tools. Two modeling alternatives are used in this example: regression analysis and neural network analysis. There are two main results: (1) Linear regression outperformed neural nets in terms of forecasting accuracy, but the opposite was true when we considered the business value of the forecast. (2) Neural net-based forecasts tended to be more robust than linear regression forecasts as data accuracy degraded. Managerial implications for financial risk management of MBS portfolios are drawn from the results.

Keywords and Phrases: Business value of information technology, data quality, decision support systems, forecasting, information economics, neural networks, mortgage-backed securities, prepayment forecasting, risk management forecasting systems, systems design.

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Alex Tuzhilin
Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

ABSTRACT: to be furnished

David Bodoff
Department of Information Systems
Stern School of Business
New York University
e-mail: dbodoff@stern.nyu.edu

ABSTRACT: Hypertext navigation alone is insufficient for efficient Information Retrieval (IR). Previous attempts to combine IR techniques with hypertext have been confined to the pre-authored structure of a document. In this paper we extend computer-science methods to synthesize a tailor-made hypertext document in response to each user's query. The synthesis technique can also be used to automatically create a pre-authored hypertext document according to an author's specifications.

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Ajit Kambil
Department of Information Systems
Stern School of Business
New York University
e-mail: akambil@stern.nyu.edu

James E. Short
Information Management
London Business School

ABSTRACT: Electronic integration - the use of information technology to reengineer key business processes and business relations - enables new forms of organization that transcend traditional industry and firm boundaries. Indeed, electronic integration strategies alter the fundamental structure of both firms as well as their environments, requiring a shift in the study of organizations from the level of a focal firm to that of the business network. The business network represents the pattern of interdependent relationships between the activities of a given firm and those of other firms in its competitive environment that influence each other's strategies.

We analyze here the effects of electronic integration on organization structure and competitive processes at the level of the business network. We propose the roles-linkage perspective as a useful abstraction to characterize the business network and guide research on the effects of information technology on industry structures. Building and analyzing the effects of electronic filing on the tax preparation market, we build a preliminary model of how electronic integration strategies alter roles and linkages in a business network.

The contributions of this article are a provisional theory of electronic integration at the level of the network, and an abstraction mechanism to characterize and study business networks.

Keywords and phrases: business network redesign, business reengineering, electronic integration, interorganizational systems.

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Shimon Schocken
Department of Information Systems
Stern School of Business
New York University
(now with Interdisciplinary Center for Business, Law, Technology, Herzliya, Israel; e-mail: schocken@idc.ac.il)

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Shimon Schocken
Department of Information Systems
Stern School of Business
New York University
(now with Interdisciplinary Center for Business, Law, Technology, Herzliya, Israel; e-mail: schocken@idc.ac.il

) ABSTRACT: During the last decade, the computational paradigms known as influence diagrams and belief networks have begun to dominate the diagnostic expert systems field. Using elaborate collections of nodes and arcs, these representations describe how propositions of interest interact with each other through a variety of causal and predictive links. The links are parameterized with inexact degrees of support, typically expressed as subjective conditional probabilities or likelihood ratios. To date, most of the research in this area has focused on developing efficient belief-revision calculi to support decision making under uncertainty.

Taking a different perspective, this paper focuses on the inputs of these calculi, i.e., on the human-supplied degrees of support which provide the currency of the belief revision process. Traditional methods for electing subjective probability functions are of little use in rule-based settings, where propositions of interest represent causally related and mostly discrete random variables. We describe ratio-scale and graphical methods for (i) electing degrees of support from human experts in a credible manner, and (ii) transforming them into the conditional probabilities and likelihood-ratios required by standard belief revision algorithms. As a secondary contribution, the paper offers a new graphical justification to eigenvector techniques for smoothing subjective answers to pair-wise elicitation questions.

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Robert J. Kauffman (now at University of Minnesota)
Stern School of Business
New York University
e-mail: rkauffman@csom.umn.edu

Dani Zweig
U.S. Naval Postgraduate School

ABSTRACT: The traditional unit of analysis and control for software managers is the software project, and subsequently the resulting application system. Today, with the emerging capabilities of computer-aided software engineering (CASE) and corresponding changes in the development process, productivity gains can be realized by reusing portions of the organization's inventory of existing application designs and code. With this opportunity, however, comes the need to monitor software reuse at the corporate level, as well as at the level of the individual software development project. Integrated CASE environments can support such monitoring. We illustrate the use and benefits of repository evaluation of software reuse through an analysis of the evolving repositories of two large firms that recently implemented integrated CASE development tools. The analysis shows that these tools have supported high levels of software reuse, but it also suggests that there remains considerable unexploited reuse potential. Our findings indicate that organizational changes will be required before the full potential of the new technology can be realized.

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Roger M. Stein
Moody's Investors Service
e-mail: rstein@stern.nyu.edu

Vasant Dhar
Department of Information Systems
Stern School of Business
New York University
e-mail: vdhar@stern.nyu.edu

ABSTRACT: This paper addresses the problem of scheduling multiple time and priority sensitive tasks efficiently in an environment where the number of resources is limited and the resources have varying capabilities and restricted capacities. We use a help desk environment as our working model, however, the methodology could also be adapted to a variety of job shop scheduling problems in general. We introduce a metric called priority time usage as a measure of task urgency and of schedule efficiency. We also introduce a method of considering user satisfaction in scheduling by utilizing fuzzy monotonic reasoning. We propose a methodology for implementing a heuristic genetic algorithm (GA) to accomplish the scheduling task. We discuss how such a system can use ongoing data about historical schedule performance to adapt and create progressively more accurate schedules in the future. We consider modifications to the scheduling approach which could allow for task inter-dependencies. We present an intuitive user interface which we developed to aid help desk administrators in using the system. In addition to providing a front end to the SOGA system, the interface allows the user of the system to perform "what if" analysis with actual schedules. Lastly, we present preliminary assessments of the utility of both the optimization engine and the user interface.

Keywords: Scheduling, genetic algorithm, fuzzy logic, constraint satisfaction problems, help desk, optimization, heuristics, graphical user interface, hybrid expert system, monotonic reasoning.

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Robert J. Kauffman (now at University of Minnesota)
Yu-Ming Wang (now at Syracuse University)
e-mail: rkauffman@csom.umn.edu

Department of Information Systems
Stern School of Business
New York University

ABSTRACT: What are the determinants of early interorganizational system (IOS) adoption? This paper focuses on a specific kind of IOS - shared electronic banking networks - and employs an economic approach that views adoption and diffusion in terms of cost and benefit. We attempt to identify firm characteristics that are likely to influence the perceived business value of network membership and develop specific hypotheses that can be tested empirically using historical data in a realistic setting. We undertake an exploratory econometric analysis of the adoption of Yankee 24, a large shared electronic banking network in the northeastern United States. Using Bass' analytical diffusion model, we categorize Yankee 24 network members into earlier and later adopters. Profit models are estimated to assess the impact of explanatory variables on shared electronic banking network adoption. The number of branch offices operated by bank, its total demand deposits, and the proportion of its total deposits accounted for by demand deposits are found to be important predictors of earlier adoption. We find that the number of branch offices operated by bank, a proxy for the size of its proprietary network, has a negative impact on early adoption, which contradicts the common wisdom that a large firm size is a prerequisite for adoption of technological innovations.

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Department of Information Systems
Stern School of Business
New York University
e-mail: tisakowit@stern.nyu.edu, hlucas@stern.nyu.edu, schocken@idc.ad.il

ABSTRACT: In spite of the increasing sophistication and power of commercial spreadsheet packages, we still lack a formal theory of a methodology to support the construction and maintenance of spreadsheet models. Using a dual logical/physical perspective, we identify four principal components that characterize any spreadsheet model: schema, data, editorial, and binding. We present a factoring algorithm for identifying and extracting these components from conventional spreadsheets with minimal user intervention, and a synthesis algorithm that assists users in the construction of executable spreadsheets from reusable model components. This approach opens new possibilities for applying object-oriented and model management techniques to support the construction, sharing, and reuse, of spreadsheet models in organizations. Importantly, our approach to model management and the Windows-based prototype that we have developed and designed to coexist with, rather than replace, traditional spreadsheet programs. In other words the users are not required to learn a new modeling language; instead, their logical models and data sets are extracted from their spreadsheets transparently, as a side-effect of using standard spreadsheet programs.

CR categories and subject descriptors: H.4.1 [Information Systems Applications]: Office Automation - Spreadsheets; H.4.2 [Information Systems Applications]: Types of Systems - Decision Support; I.6.4 [Simulation and Modeling]: Model Validation and Analysis; I.6.5 [Simulation and Modeling]: Model Development; K.8.1 [Personal Computing]: Application Packages - Spreadsheets. General terms: Theory, design, languages.

Additional key words and phrases: model management

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Robert J. Kauffman (now at University of Minnesota)
Stern School of Business
New York University
e-mail: rkauffman@csom.umn.edu

Robert M. Mark (now at Canadian Imperial Bank of Commerce, Toronto)
Chemical Banking Corporation

Edward Peters
The HAY Group, Inc.
Washington, D.C.

ABSTRACT: Methods for sound risk management are of increasing interest among Wall Street investment banking and brokerage firms in the aftermath of the October 1987 crash of the stock market. As the knowledge of advanced technology applications in risk management increases, financial firms are finding innovative ways to use them practically, in order to insulate themselves. The recent development in models, the software and hardware, and the market data to track risk are all considered advances in Risk Management Technology (RMT). These advantages have affected all three stages of risk management: the identification, the measurement, and the formulation of strategies to control financial risk. This article discusses the advances made in five areas of RMT: communication software, object-oriented programming, parallel processing, neural nets and artificial intelligence. Systems based on any of these areas may be used to add value to the business of a firm. A business value linkage analysis shows how the utility of advanced systems can be measured to justify their costs.

Keywords: Risk management, object-oriented, neural nets, artificial intelligence, business value, client server, distributed database, parallel processing, pattern recognition, data quality.

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Robert J. Kauffman (now at University of Minnesota)
Laura Lally (now at Hofstra University)
e-mail: rkauffman@csom.umn.edu

Department of Information Systems
Stern School of Business
New York University

September 15, 1993

ABSTRACT: Customer access information technologies (CAITs) provide a link between a firm and its customers. Firms invest in CAITs to reduce costs, increase revenues and market share, lock in existing customers and capture new ones. These benefits, however, are notoriously difficult to measure. This paper proposes an evaluative method for CAIT deployment called value platform analysis, that is based on a conceptual model drawn from the theory of retail outlet deployment in marketing science. The model focuses on the impact of CAIT features and environmental features on transactions generated by the CAIT. Specific econometric models are developed for deployment. Hypotheses regarding the likely impact of automated teller machine (ATM) location design choices and environmental features on ATM transactions are evaluated. The results indicate that there are a number of key features influencing ATM performance. Two distinct ATM deployment scenario emerge: one for servicing a bank's own customers, and another for providing transaction services for customers for a fee.

Keywords: Automated teller machines, customer access information technology, electronic banking, information technology, electronic banking, information technology, IT deployment, IT value, systems design, value platform analysis.

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Kenneth C. Laudon
Department of Information Systems
Stern School of Business
New York University
e-mail: klaudon@stern.nyu.edu

December 1993
Revised Draft Version July 1993

ABSTRACT: Since the 1960s privacy advocates have relied on regulatory and legislative approaches to privacy protection in the United States, Canada and Europe. While important progress has been made in certain areas, there are large gaps and significant loopholes in existing legislation. I argue that a market-based approach to privacy protection would be far more effective and efficient in protecting individual information than current approaches.

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Alexander Tuzhilin
Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

ABSTRACT: Temporal logic queries on Datalog and negated Datalog programs are studied, and their relationship to Datalog queries on these programs is explored. It is shown that, in general, temporal logic queries have more expressive power than Datalog queries on Datalog and negated Datalog programs. It is also shown that an existential domain-independent fragment of temporal logic queries has the same expressive power as Datalog queries on negated Datalog programs with inflationary semantics. This means that for finite structures this class of queries has the power of the fixpoint logic.

Keywords and Phrases: Datalog, temporal logic queries, expressive power.

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Alexander Tuzhilin
Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

ABSTRACT: A high level simulation language based on temporal logic is described. The language combines a large set of temporal tenses and a rich class of high level modeling primitives. Also an implementation of the language interpreter is presented. Finally, a real world case study is described that shows how a programmer can develop structured, reliable, and well-maintained simulation programs using the language.

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Shimon Schocken
Department of Information Systems
Stern School of Business
New York University
(now with the Interdisciplinary Center for Business, Law, and Technology, Herzliya, Israel. e-mail: schocken@idc.ac.il)

Robert A. Hummel
Courant Institute
New York University
e-mail: hummel@cs.nyu.edu

ABSTRACT: The Dempster Shafer theory of evidence concerns the elicitation and manipulation of degrees of belief rendered by multiple sources of evidence to a common set of propositions. Information indexing and retrieval applications use a variety of quantitative means - both probabilistic and quasi-probabilistic - to represent and manipulate relevance numbers and index vectors. Recently, several proposals were made to use the Dempster Shafer model as a relevance calculus in such applications. The paper provides a critical review of these proposals, pointing at several theoretical caveats and suggesting ways to resolve them. The methodology is based on expounding a canonical indexing model whose relevance measure sand combination mechanisms are shown to be isomorphic to Shafer's belief functions and to Dempsters' rule, respectively. Hence, the paper has two objectives: (i) to describe and resolve some caveats in the way the Dempster Shafer theory is applied to information indexing and retrieval, and (ii) to provide an intuitive interpretation of the Dempster Shafer theory, as it unfolds in the simple context of a canonical indexing model.

Keywords: Theory of evidence, Dempster-Shafer model, relevance measures, information indexing and retrieval.

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Bruce W. Weber
Department of Information Systems
Stern School of Business
New York University
e-mail: bweber@stern.nyu.edu

June 10, 1993

ABSTRACT: Electronic markets use information technology to disseminate information on prices, quantities, and buyer and supplier identities. In spite of the recognized benefits of electronic markets, increased visibility and transparency may introduce imperfections, and create profitable opportunities to bypass markets that generates the information. In the U.S. securities markets, dissemination of market data has equipped several firms to develop competing, off-exchange trading mechanisms that rely on market price data, but whose transactions bypass the established market. Concern is rising that the growing volume of trading occurring away from the main market may reduce liquidity, and increase transactions costs. A simulation model of securities trading in a continuous auction market (similar to the market structure of the New York Stock Exchange) is used to examine the market quality effects of increasing levels of trading activity through an off-exchange dealer. Market characteristics, such as transactions costs, are measured as off-exchange trading increases from zero percent to 20 percent of the total trading volume. The results indicate that competition from an alternative trading venue reduces some trading costs borne by investors. Contrary to regulatory goals, however, off-market trading expands the role of profit-seeking dealers, and lower the probability that some investors' orders will execute.

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Shimon Schocken
Department of Information Systems
Stern School of Business
New York University
(now with the Interdisciplinary Center for Business, Law, and Technology, Herzliya, Israel. e-mail: schocken@idc.ac.il)

Robert A. Hummel
Courant Institute
New York University
e-mail: hummel@cs.nyu.edu

June 16, 1993

ABSTRACT: We consider a situation in which multiple decision-makers who are partitioned into two or more distinct groups are asked to recommend a uniform course of action which is drawn from a finite and explicit set of potential alternatives. We present group-level and player-level mechanisms to reach a compromise decision under such circumstances. The group-level mechanism is based on the Dempster-Shafer theory of evidence; The player-level mechanism employs a set-product operation that aggregates the individual decision over a certain space of committees. Previous research established that the two mechanisms are isomorphic, which, in the context of the present paper, implies that they yield the same compromise decision. However, unlike the Dempster-Shafer theory, which was criticized for lack of external validity, the set-product mechanism has plausible properties in the context of group decision making. With that in mind, the paper seeks to (I) report about an interesting relationship between group decision research and AI methods to manage uncertainty, and (ii) build a foundation for an inter-disciplinary research that exploits this linkage.

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Henry C. Lucas, Jr.
Department of Information Systems
Stern School of Business
New York University
e-mail: hlucas@stern.nyu.edu

Laurence Caby
Institute Nationale de Telecommunications
Evry, France

ABSTRACT: An open data network is one that allows firms to exchange information with outside entities, and a national data network is one that provides virtually universal access, interconnecting most businesses and private citizens in a country. Establishing a national data network is very costly and must be justified by its economic, service, and societal impact. France with its Teletel system is close to having a national data network, whereas the United States is not. Using data from 619 businesses in France and the United States we examine several claims: 1) open networks have improve firms' productivity, efficiency, and quality of service; 2) national open networks allow relationships among firms to be based on an electronic marketplace; and 3) national open networks differentially benefit small and medium sized firms. The results show that firms using open networks are more efficient and profitable and have more stable relationships with their customers. The natural advantage that large firms have to exploit new technology has been moderated in France, since small and medium-sized firms who used the national network.

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Bruce W. Weber
Department of Information Systems
Stern School of Business
New York University
e-mail: bweber@stern.nyu.edu

April 7, 1993

ABSTRACT: Financial markets perform a seemingly simple function: facilitating the transfer of securities into cash, or cash into securities. Closer inspection of the activities and the information intensity of a trading floor or a dealing room reveals great complexity. Information technology (IT) plays a crucial role in supporting market activities, and no trader today could operate without real-time data services, and computer-based analytical tools. Market information - about prices, interest rates, transactions, investor supply and demand, and company and economic news - is at the heart of any trading operation. Consequently, the major international markets from Tokyo to Zurich are making increased use of information technology. While IT is capable of making physical marketplaces and trading floors obsolete, no consensus is emerging on the design of an integrated global financial market, and many technological and regulatory issues remain unsolved. Multiple, fragmented markets may be a consequence of the lack of coordination. This chapter highlights the technologies that are revolutionizing international financial markets. The future direction of financial markets will be charted by automation and systems, and IT's influence on banks, securities firms, and the markets themselves will continue to be a subject of debate and controversy.

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Department of Information Systems
New York University
Stern School of Business
e-mail: atuzhili@stern.nyu.edu or vdhar@stern.nyu.edu

ABSTRACT: In this paper, we study the problem of discovering interesting patterns in large volumes of data. Patterns can be expressed not only in terms of the database schema but also in user-defined terms, such as relational views and classification hierarchies. The user defined terminology is stored in a data dictionary that maps it into the language of the database schema. We define a pattern as a deductive rule expressed in user-defined terms that has a degree of certainty associated with it. We present methods of discovery interesting patterns based on abstracts which are summaries of the data expressed in the language of the user.

Keywords: pattern discovery, data abstraction, classification, generalization.

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Tomas Isakowitz
Department of Information Systems
Stern School of Business
New York University
e-mail: [Return to top of the page]

Department of Information Systems
Stern School of Business
New York University
e-mail: atuzhili@stern.nyu.edu

March 24, 1993

ABSTRACT: Numerous proposals for extending the relational data model to incorporate the temporal dimension of data have appeared in the past several years. These proposals have differed considerably in the way that the temporal dimension has been incorporated both into the structure of the extended relations of these temporal models, and consequently into the extended relational algebra or calculus that they define. Because of these differences it has been difficult to compare the proposed models and to make judgments as to which of them might in some sense be equivalent or even better. In this paper we define the notions of temporally grouped and temporally ungrouped historical data models and propose two notions of historical relational completeness, analogous to Codd's notion of relational completeness, one for each type of model. We show that the temporally ungrouped models are less expressive than the grouped models, but demonstrate a technique for extending the ungrouped models with a grouping mechanism to capture the additional semantic power of temporal grouping. For the ungrouped models we define three different languages, a temporal logic, a logic with explicit reference to time, and a temporal algebra, and show that under certain assumptions all three are equivalent in power. For the grouped models we define a many-sorted logic with variables over ordinary values, historical values, and times. Finally, we demonstrate the equivalence of this grouped calculus and the ungrouped data models into grouped and ungrouped provides a useful framework for the comparison of models in the literature, and furthermore the exposition of equivalent languages for each type provides reasonable standards for common, and minimal, notions of historical relational completeness.

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Michael Bieber
Department of Information Systems
Stern School of Business
New York University
now with:
Institute of Integrated Systems Research
Department of Computer and Information Science
New Jersey Institute of Technology
Newark, NJ
e-mail: bieber@cis.njit.edu

ABSTRACT: not available

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Henry C. Lucas, Jr.
Gregory E. Truman (now at Fordham University)
Donald J. Berndt (now at University of South Florida)
Department of Information Systems
Stern School of Business
New York University
e-mail: hlucas@stern.nyu.edu

February 8, 1993

ABSTRACT: Re-engineering or business process redesign has become very popular. This paper presents a clear description of re-engineering and contrasts it with incremental change in systems. The paper also develops a framework for comparing two related systems. The framework is applied to a case study of the re-engineering of the Merrill Lynch Securities Processing System. This system features image processing, character recognition and extensive process redesign. The re-engineering effort has had a substantial impact on the firm.

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