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Published Papers

These are the papers that EII has published in professional journals or conferences. In most cases EII does not hold the copyright to these papers; thus we can only provide the links to the relevant websites from which the papers may be downloaded.

Interactive Multiobjective Complex Search
"Interactive Multiobjective Complex Search," The European Journal of Operational Research, Vol. 19 (1985), 365-371 (with J.L. Ringuest). An interactive procedure based on Box's complex search is used to solve the vector maximization problem. This method has the advantage that the decision maker's underlying value function need not be explicitly specified. Also, the problem may have nonlinear objective functions and nonlinear constraints. Several example problems are presented.
Interfaces for Enterprise Solutions
This paper was published in the Journal of Enterprise Architecture, Vol. 1, No. 1, August 2005. This document discusses fundamental interface concepts, interface models, and interface cost analysis. By having an understanding of interface technology and cost factors, system architects are better equipped to design and deploy cost-effective interface models.
Investment in Knowledge: A Generalization of Learning by Experience
"Investment in Knowledge: A Generalization of Learning by Experience," Management Science, Vol. 40 (1994), 947-958. (with J.R. Dorroh and N.K. Womer). Learning is often perceived as a cost-reducing endogenous by-product of production processes. In many applications this by-product is modeled as a learning curve; that is, a simple function of time or of cumulative production experience. In an earlier paper we presented an alternative explanation where managers decide what resources to devote to knowledge acquisition. In this paper we expand those results to a situation using a more flexible production technology and emphasizng discounted cost. Our model explains resource and output behavior for a firm that is producing specialized units to contractual order. However, the results are quite general and have implications for investment in research, engineering, science and technology, software development, and worker training. We provide examples where the cost-minimizing producer will choose to invest in knowledge creation early in the production program and then have the rate of investment decline over time. Other interesting results are noted by examining the optimal time paths of the control and state variables in a comparative dynamics analysis.
Learning and Costs in Airframe Production
"Learning and Costs in Airframe Production: A Multiple Output Production Function Approach," The Naval Research Logistics Quarterly, Vol. 31 (1984), 67-85 (with N.K. Womer and J.R. Dorroh). This article examines the influence of both production rate and learning on airframe program costs. A dynamic multiple-output production model is developed and is used to observe the cost impact of changes in production rate and learning. Several simulations are performed to demonstrate the sensitivity of the optimal time path of cost to changes in the model parameters. The model is applied by estimating parameters from the F102 airframe program.
Learning and Production Costs: An Application of a Cost Prediction Model to a Fighter Airframe Program
"Learning and Production Costs: An Application of a Cost Prediction Model to a Fighter Airframe Program," Engineering Costs and Production Economics, Vol. 12 (1987), 389-400 (with J.D. Camm and N.K. Womer). This research reports on the application of a cost prediction model to a fighter airframe program. The model considers the effects of learning and production rate changes on discounted program cost. The results indicate that this application compares favorably with those of other programs reported previously.
Learning Curves and Production Functions: An Integration
"Learning Curves and Production Functions: An Integration," Engineering Costs and Production Economics, Vol. 20 (1990), 3-12 (with N.K. Womer). This paper explores a class of dynamic cost models that are designed for made-to-order production and are particularly applicable to the airframe industry. In these models we use optimal control theory to describe the time paths of resource use and production rate. The analytic solution for the most general specification of the model is unknown, however the imposition of a restriction on the relation between production rate and experience rate leads to a straightforward solution. The model implies that there exists an optimal trade-off between learning and production rate during the life of a program and that production rate should be changing throughout the life of the program in order to minimize cost. The model is compared with the learning curve, and the applicability of the model is explored by performing various parametric sensitivity analyses. The model's behavior is consistent with the dynamics of actual made-to-order production programs.
Modeling an Enterprise Services Enabled Product Improvement Process for Military Vehicles
Paper no. DETC2008-49922 pp. 1277-1291 (15 pages) doi:10.1115/DETC2008-49922 ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDETC/CIE2008) August 3–6, 2008 , Brooklyn, New York, USA Sponsor: Design Engineering Division and Computers in Engineering Division Volume 3: 28th Computers and Information in Engineering Conference, Parts A and B ISBN: 978-0-7918-4327-7. The evolution of Enterprise Services is changing the approach for enabling Product Lifecycle Management (PLM) and Supply Chain Management (SCM). Enabling systems are migrating to process- and service-oriented solutions, requiring new approaches for architecting composite applications. This paper uses examples from our work to present the state-of-the art in architecting end-to-end solutions for delivering PLM and SCM capabilities from an Original Equipment Manufacturer (OEM) to the customer. The paper also demonstrates how emerging methodologies, methods, and tools are used to support the implementation of composite applications, as well as the limitations of working in a mixed legacy/modern environment during the lengthy transition period to the new service-oriented computing paradigm. The hypothesis of this paper is that design and supply chain integration is achievable through composite application design, development, and deployment. This paper discusses the design, development, and deployment of a composite application to address the product improvement process for military vehicles, and it lays the foundation for testing the hypothesis. Based on these initial analyses we conclude that the composite approach to PLM is not only feasible, but may provide the only practical solution (given current technologies) to a very complex supply chain information sharing problem.
Probability Plotting Positions and Goodness of Fit
"Probability Plotting Positions and Goodness of Fit," The Statistician, Vol. 34 (1985), 297-303 (with S.W. Looney). This paper considers the problem of choosing a plotting position to use in constructing a normal probability plot. Previous recommendations have focused primarily on choosing a position so that the resulting plot will yield the best possible graphical estimates of either the standard deviation or the quantiles of the hypothesised distribution. In this paper, emphasis is placed on choosing a plotting position so that the resulting plot is best able to detect departures from normality. Seven plotting positions are compared using empirical power results for correlation coefficient test statistics that are calculated directly from probability plots. The comparisons indicate that correlation tests based on six of the plotting positions have almost identical power and that the choice of a plotting position depends primarily on ease of use.
Process Coupling in Business Process Engineering
"Process Coupling in Business Process Engineering," Knowledge and Process Management, Vol. 6 (1999), 158-165 (with R. Sommer). Many Business Process Engineering (BPE) methods focus on information flows, function identification and process decomposition. Although these concepts are important, the authors have found that the consistent assignment of performance measures, policies, and regulations are of equal importance. Inconsistent performance measures and policy formulation and review result in significant implementation problems in a BPE effort. This paper identifies Process Coupling as the result of inconsistent performance measures, policies, and regulations; and with the help of a case study, demonstrates how the resulting implementation problems may be alleviated.
Product Lifecycle Management in Defense Organizations: Challenges and Opportunities
by Gulledge, Thomas — last modified May 06, 2010 01:08 AM Contributors: Wael Hafez, Senior Enterprise Architect, Enterprise Integration, Inc., Raj Iyer, Deputy Chief Technology Officer, U.S. Army Materiel Command, John Nyere, Special Assistant for Supply Chain Systems, Office of the Secretary of Defense, U.S. Department of Defense. Product Lifecycle Management (PLM) presents many unique challenges in defense organizations. These challenges relate culture, organization, processes, data, and others. While some of these characteristics are not unique to defense organizations, some are specifically unique. This paper identifies and describes the challenges, and then presents an approach to requirements definition and solution design that addresses the described challenges. A closed-loop PLM model requires that the government take ownership of the product, post production, and assume every aspect of product support. This would include supply, procurement, maintenance, operations, engineering, configuration and fleet management functions. (C) 2010 Enterprise Integration, Inc. All Rights Reserved. Presented at The IFIP WG5.1 7th International Conference on Product Lifecycle Management, BIBA University of Bremen, 12-14 July 2010.
Production Rate, Learning, and Program Costs: Survey and Bibliography
"Production Rate, Learning, and Program Costs: Survey and Bibliography," Engineering Costs and Production Economics, Vol. 11 (1987), 223-236 (with B. Khoshnevis). This survey contains items that we have found useful in our integrative research on production rate, learning, and cost. The references given relate to aggregate planning, assembly line balancing, and overhead redistribution. The survey is narrow in that it only relates to learning augmented production models that contain production rate as a decision variable. General references to the learning curve are not included. We make no claims that this survey is complete. Our efforts have concentrated on the economics, industrial engineering, and operations research literature. The authors solicit omitted items for inclusion in future revisions.
Promoting Electronic Commerce in the Defense Industry
“Promoting Electronic Commerce in the Defense Industry,” In Electronic Commerce: Opportunities and Challenges, S.M. Rahman and M.S. Raisinghani (Editors). Hershey, Pennsylvania: Idea Group Publishing, 2000, 85-101 (with C.V. Trappey, A.J.C. Trappey, and R. Sommer). Beginning in 1993, when the U.S. Federal Government proposed the "framework of electronic commerce (EC)," the call went out for the wide-scale deployment of EC solutions in government. The Department of Defense immediately became the center of attention since it has the largest procurement budget of all. Initiatives were launched to move from a paper-driven procurement process to an electronic, on-line concept satisfying federal mandates. However, the defense industry consists of thousands of small and medium sized enterprises (SMEs) that were far from ready to conduct business with the government electronically. In order to help the Department of Defense (DoD) and its suppliers to comply with the EC mandates, 17 Electronic Commerce Resource Centers (ECRCs) were established across the U.S. to transfer process improving and enabling EC technologies to small and medium sized businesses and government agencies. Each ECRC comprises business partners (and several university partners) that provide EC outreach, training and technical support to DoD supply chains. The goal of the nationwide network of centers is to facilitate the transition from paper-dependent supply chains to fully electronic-based procurement environments. In order for SMEs to do business with the U.S. government electronically, the mission of the ECRC must grow beyond training and outreach to hands-on implementation and intervention in SMEs.
Public Sector Reengineering: Applying Lessons Learned in the Private Sector to the U.S. Department of Defense
“Public Sector Reengineering: Applying Lessons Learned in the Private Sector to the U.S. Department of Defense,” In Business Process Reengineering: A Managerial Perspective, V. Grover and W.J. Kettinger (Editors). Harrisburg: Idea Group Publishing, 1995 (with D.H. Hill and E.H. Sibley). The management of the US Department of Defense (DoD) enterprise must change. Years of under-funding have led to a wide gap between enterprise support requirements and resources. Private sector firms have faced similar choices. This paper shows how the public enterprise can be changed. Our hypothesis is that private sector implementations of standard software will lead to increased effectiveness and efficiency in public sector organizations. Sufficient detail is provided on how to transition to a modern integrated public sector enterprise, and the steps for implementing such a project are outlined, following standard private sector implementation practices. To explain the problem and solution, the DoD installation management enterprise is used as an example.
Regression Tests of Fit and Probability Plotting Positions
"Regression Tests of Fit and Probability Plotting Positions," The Journal of Statistical Computation and Simulation, Vol. 20 (1984), 115-127 (with S.W. Looney). Probability plots are commonly used as a technique for testing distributional assumptions. However, any conclusion about the linearity of such a plot is based strictly on the user's judgment. Regression tests of fit are supposed to make this procedure more objective, but these tests typically are not based on probability plots as they are constructed in practice. This is because the developers of these tests defined probability plots in terms of plotting positions which are not used by practitioners. In this paper, a class of goodness-of-fit test statistics which are calculated directly from probability plots as they are constructed in practice is described. Several realistic plotting positions for the normal distribution are chosen and empirical sampling methods are used to derive the null distribution of each of the corresponding test statistics. These tests are then compared on the basis of 5% power against certain nonnormal alternatives. Results of the comparisons indicate that the test based on the plotting position is a reasonable choice for a powerful regression test of fit for normality.
Resource Efficiency in Aircraft Production
"Resource Efficiency in Aircraft Production," Naval Research Logistics, Vol. 35 (1988), 443-58 (with B. Dhar). This article examines measures of economic efficiency in aircraft production. In particular, a type of nonlinear frontier estimation is contrasted with more traditional methods for estimating a dynamic cost function. This cost function is grounded in economic theory, and it is consistent with knowledge of the aircraft-production process. The model includes the effects of both learning and production rate on total program costs. The usefulness of the model is demonstrated with an example that relates to the acquisition of military equipment. It is shown through various sensitivity analyses that an alternative procurement policy for an aircraft program could have resulted in increased efficiency and hence a lower total program cost to the government.
Service-oriented concepts: bridging between managers and technologists
Thomas Gulledge, Greg Deller, (2009) "Service-oriented concepts: bridging between managers and technologists", Industrial Management & Data Systems, Vol. 109 Iss: 1, pp. 5-15. The purpose of this paper is to provide a common understanding of service-oriented concepts to enable unambiguous discussion around service-oriented architecture (SOA). Managers often have limited understanding of SOA, and for some reason, technologists seem to have difficulty explaining the concept using terminology and analogies that managers can understand. This paper addresses the long-standing communications gap between managers and technologists as they attempt to evaluate how SOA or SOA-related investments can add business value.
Spectral Analysis of Nominal Interest Rates
"Spectral Analysis of Nominal Interest Rates," The Journal of Economic Dynamics and Control, Vol. 11 (1987), 275-281 (with Ü. Erol and J.A. Richardson). [Abstract not available]
Subjective Evaluation of Composite Econometric Policy Inputs
"Subjective Evaluation of Composite Econometric Policy Inputs," Socio-Economic Planning Sciences, Vol. 20 (1986), 51-55 (with J.L. Ringuest and J.A. Richardson). Studies have suggested that a composite forecast may be preferred to a single forecast. In addition, forecasting objectives are often conflicting. For example, one forecast may have the smallest sum of absolute forecast errors, while another has the smallest maximum absolute error. This paper examines the appropriateness of using multiple objective linear programming to determine weighted linear combinations of forecasts to be used as inputs for policy analysis. An example is presented where the methodology is used to combine the forecasts for several policy variables. The forecasts are selected from large econometric, consensus, and univariate time series models.
The n-Tier Hub Technology
by Sommer, Ray. Contributors: Thomas Gulledge, David Bailey ACM SIGMOD Record, Vol. 31 #1 (March, 2002). During 2001, the Enterprise Engineering Laboratory at George Mason University was contracted by the Boeing Company to develop an eHub capability for aerospace suppliers in Taiwan. In a laboratory environment, the core technology was designed, developed, and tested, and now a large first-tier aerospace supplier in Taiwan is commercializing the technology. The project objective was to provide layered network and application services for transporting XML-based business transaction flows across multi-tier, heterogeneous data processing environments. This paper documents the business scenario, the eHub application, and the network transport mechanisms that were used to build the n-tier hub. Contrary to most eHubs, this solution takes the point of view of suppliers, pushing data in accordance with supplier requirements; hence, enhancing the probability of supplier adoption. The unique contribution of this project is the development of an eHub that meets the needs of Small and Medium Enterprises (SMEs) and first-tier suppliers.
The US Navy enterprise resource planning architecture
by Gulledge, Thomas. Contributors: Ray Sommer, Georg Simon Published in Electronic Government, Vol. 1, No. 4, 2004. This paper presents the design of the US Navy's enterprise resource planning (ERP) architecture, which takes the as-configured baseline across multiple ERP projects, and transforms it into a converged to-be integrated solution. The result is an architecture-based instance consolidation that is unique; for the Navy solution is the first architecture-driven instance consolidation.