Application Of Operations Research Techniques Research Articles

Efficient Supply Chain Management at the U.S. Coast Guard Using Part-Age Dependent Supply Replenishment Policies

The United States Coast Guard (USCG), now part of the Department of Homeland Security, has the mission to secure the U.S. coastline using a combination of air and sea capabilities. This paper focuses on an application of operations research techniques at the USCG to improve the performance of its aircraft service parts supply chain. We focused on evaluating the supply chain benefits from linking the aircraft maintenance database with the aircraft parts inventory database. This required us to (a) develop an approach to link the databases and (b) use aircraft maintenance information to improve the inventory management of service parts at the USCG. We first used mathematical programming tools to merge the maintenance database with the demand database. We then developed state-dependent supply replenishment policies that use part-age information to manage the service parts supply chain. We show that one of the proposed policies permits analytic estimation of the benefits of linking the data sets. The impact of these inventory policies was evaluated using empirical demand data for 41 critical parts over a five-year period. Computational results suggest that our proposed policies can lead to significant reductions in inventory cost over the current system, as high as 70% for some parts. Based on the insights from this study, the USCG is currently contracting with commercial vendors to develop an operational database and decision-support implementation across all parts.

From the Guest Editor—Special Cluster on Operations Research in Electrical and Computer Engineering

My research in optimization at the Department of Systems and Computer Engineering at Carleton University has brought me into contact with researchers in the Department of Electronics, our sister department in the general field of Electrical and Computer Engineering (ECE), which has a major research thrust in computer-aided design (CAD) of very large scale integrated (VLSI) circuits. I have come to realize that the design of VLSI systems consists in large part of solving incredibly massive mixed-integer nonlinear optimization problems, together with enormous circuit simulations. This is impossible without the use of CAD techniques. Over time, ECE-CAD researchers have both borrowed useful standard techniques from operations research (OR) and have invented their own, often to deal with the sheer scale and complexity of the design problems they face. Interaction between the OR and ECE-CAD communities would seem to be a natural development. Coincidentally, the INFORMS Journal on Computing had an area entitled “High Performance Computation” that covered (i) the solution of OR problems using new computing technologies, (ii) the application of OR techniques in the design and use of highperformance computing and communication systems, and (iii) solution methods for ultra-large-scale OR applications. The viability of this area was debated during 2003 as some of its aspects migrated to other areas (e.g., the new “Telecommunications and Electronic Commerce” area), and the number of submissions declined. The area was eventually closed, although I argued that the overlap between OR and ECE-CAD, essentially covering items (ii) and (iii), was a very active research area. This Special Cluster of papers was conceived as a way to test that argument. I was recruited at the same time to prepare a tutorial on ECE-CAD for the 2004 INFORMS Annual Meeting (see John W. Chinneck, Michel Nakhla, and Q. J. Zhang 2004. Computer-aided design for electrical and computer engineering. H. J. Greenberg, ed. Tutorials on Emerging Methodologies and Applications in Operations Research. Springer, New York, 6-1 to 6-44). The preparation of the article reinforced my observation about the research overlap between OR and ECE-CAD. A search of the electrical engineering literature for 2000 through early 2004 turned up 46,725 papers mentioning “simulate” or “simulation” as keywords in the abstract, 14,216 papers mentioning “optimization” or “optimize,” and relatively smaller numbers for specific techniques such as “neural network” (6,251), “genetic algorithm” (2,603), “linear programming” (576), “simulated annealing” (448), and “branch and bound” (199). One surprise was the relatively small number of papers using the generic keywords “mathematical programming” (68) or “operations research” (37). The general conclusion of the tutorial article is that the OR and the ECE-CAD communities have much to offer each other. This is certainly the case for the papers gathered in this Special Cluster. We see known OR techniques adapted for use in ECECAD. In “Integer Linear Programming Models for Global Routing,” Behjat et al. apply integer linear programming in a heuristic to solve enormous NPhard connection routing problems for VLSI circuits. In “Task Scheduling in a Finite-Resource, Reconfigurable Hardware/Software Codesign Environment,” Loo and Wells use simulated annealing, genetic algorithms, and random search techniques to solve scheduling problems in hardware-software co-design. We also see new techniques specifically developed by the ECE-CAD community to deal with problems of extreme scale. In “A Projection-Based Reduction Approach to Computing Sensitivity of Steady-State Response of Nonlinear Circuits,” Pai et al. develop methods for sensitivity analysis in extremely large nonlinear programs, especially those in which the objective function is very costly to evaluate. The methods have special relevance for simulation-based

The assignment of workers to tasks - An example from an academic department

A description is given of the application of Operations Research techniques to the problem of assigning lecturers to tasks in an academic department. All the steps in the approach are described - from the collection of the data through the building of a mathematical model to the implementation of the solution. Two approaches to obtaining a solution are described. Firstly a heuristic method is shown which can be done with pencil and paper. The solution obtained with this method can be used for implementation, or it can be used as a starting solution for the computer package used for the solution of the mathematical model.

The Application of Operations Research Techniques to Financial Markets

This paper reviews the application of OR to financial markets. After considering reasons for the attractiveness of general finance problems to OR researchers, the main types of financial market problem amenable to OR are identified, and some of the many problems solved using OR are documented

Linear programming approaches to the measurement and analysis of productive efficiency

An important and rapidly growing empirical application of operations research techniques involves the measurement and analysis of the efficiency with which goods are produced and services are provided. The production activities whose efficiency has been the subject of investigation have varied widely, from profit-oriented industrial manufacturing enterprises all the way to public and private service providers operating in a not-for-profit environment. A similarly wide variety of operations research techniques has been utilized in the measurement and analysis of productive efficiency, ranging from stochastic parametric regressionbased methods to nonstochastic nonparametric mathematical programming methods. Foremost among the latter is a family of linear programming models collectively referred to as Data Envelopment Analysis (DEA). The purpose of this paper is to provide a selective overview of some of the most useful DEA models. I analyze these models in terms of their ability to accurately reflect the structure of the underlying production technology, their ability to accurately measure the productive efficiency of the producers being analyzed, and their data requirements and their sensivity to shortcomings in the data that form the basis of the analysis. The selectivity of the overview reflects my talents and my interests. Thus the orientation of the overview is toward the user of existing DEA models, not toward the developer of new models. In particular, the review is intended to inform practitioners in the fields of management science, economics and public administration who want to learn and

Entropy of plagues: A measure for assessing the loss of social cohesion due to epidemics

We have asked the question what kind of illumination might be given to a series of historical events through the application of operations research techniques. The question is addressed by means of a model. In that model we compare the evidence for the collapse of civil authority during selected plagues of the 14th–17th century against the value for a casualty based entropy. The entropy is computed from time series of mortality data taken from the historical record of the selected period. This contribution builds upon previously published work in which entropy, computed from military casualties, becomes a predictor of combat outcome. The conjecture is advanced that mortality based entropy calculations reveal the impact of the plague mortality on societal structure Comparison with the work of Dupaquier on the scaling crises is made. Suggested extensions to additional societal phenomena are advanced.

Packing problems

This survey considers the application of Operational Research techniques to the solution of packing problems. Such problems arise in a variety of situations including pallet loading, container stuffing and placement problems. The focus of this paper is on the modelling and solution of problems in two and three dimensions and a number of exact and heuristic approaches are reviewed.

Locating Rural Social Service Centers in India

This paper describes experience with application of operations research techniques in planning new roads and social service centers for the Dharampur area in India. The work involved designing a road network using a minimal spanning tree algorithm; selecting the number and location of the service centers to be constructed over a five year period using a set covering algorithm; and developing a schedule for the construction of the service centers using dynamic programming. Substantial economic benefits resulted from using the mathematical models. The experience shows that operations research models can be useful in providing an objective rationale for administrative decisions, thus playing an important role in the resolution of political conflict.

Ten years progress in quantitative research on libraries

Approximately ten years ago there developed a widespread interest in the application of Operations Research techniques to library problems. An extensive body of literature now exists. However, implementation has been limited and some important topics have been neglected. This survey reviews the areas in which most work has been done, identifies neglected areas and concludes that the progress and lack of it is typical of the application of quantitative research in social service situations. Numerous references are made to the literature.

Operations research in postal services—a survey

The collection, processing and delivery of letters and packages comprise one of the largest service industries in the world. This paper provides a broad survey of the application of operations research techniques to analyze and resolve decision problems forced by postal managers in various countries. The problem areas considered include: forecasting, cost and revenue analysis, postal network design, manpower planning and scheduling, maintenance, and service characteristic measurement. The paper concludes with a brief description of the efforts to train postal managers in the use of operations research in their decision-making functions.

Bibliography of Operations Research in Health-Care Systems

This paper presents a bibliography of the articles that were published before March 1976 and that describe applications of operations research techniques to health-care delivery systems.

Optimization of state water quality monitoring systems

The water quality monitoring activities required of the States under the Federal Water Pollution Control Act Ammendments (PL92-500) will require resources well beyond what is likely to be available, if current systems structures and operating procedures are followed. This paper describes some quantitative procedures developed to optimize monitoring resource allocation, with the goal of getting the greatest possible return on a limited monitoring budget. The ambient and effluent standards which form the basis of the monitoring system are described. Stochastic inputs to the river basin which lead to violations of these standards are identified, and progress in characterizing these variations mathematically is discussed. Quantitative priority-setting procedures for the two principal monitoring activities (ambient and effluent), which take into account these stochastic inputs, are reviewed. Both procedures are designed to tell the state agency planner where the next increment of resource should be expended to maximize alternative monitoring objective functions. Approaches to integrating these two primary monitoring functions and opportunities for further applications of operations research techniques to improve program effectiveness and efficiency are suggested.

A concept of an integrated transport model

This paper is one of a series being produced on the application of Operational Research techniques in the integrated planning of public service resource provision and consumption. It describes a conceptual basis for planning transportation services within the context of a public service, the others are related to Health Services, Educational Services and community development services. Two sub-models, a linear sub-model and a dynamic sub-model are linked to form the integrated approach to the planning problem. The overall concept is to evaluate in terms of penalties and benefits the alternative plans of resource provisions. It is of interest to know that the principles of the Linear model described here has been applied to long range planning in the Health Service in the U.S.A. and U.K., and has been reported at the NATO conference, Portugal (1974). The Dynamic model has been used, in a more unstructured fashion than described here, by the Greater London Councils. The model in this paper is to form the basis of a more detailed evaluation of alternative transportation plans.

A Dynamic Programming Approach to Optimal Grazing Strategies Using a Succession Model for a Tropical Grassland

This paper shows an application of operations research techniques for promotion of decision making in grazing management. The research described here simulated grass-land succession on an Indian grassland on the basis of plant cover data collected for two successive years in pastures having different intensities of grazing. The succession simulation was developed using a transfer matrix for yearly change of plant cover between species. Transfer functions were then developed for each of four intensities of grazing from ungrazed to heavily grazed. These were used in developing a long-term optimal grazing pattern using dynamic programming. The objective function was not simply to optimize utilization, but was to achieve a combined objective involving diversity, leguminous plants, bare space, and the density of the dominant forage plant Dichanthium annulatum as well as utilization. Results from the optimization show a combination of moderate grazing with an occasional light grazing year as the best grazing strategy for our objectives over a 12-year grazing horizon.

Status of Water Resource Systems Analysis

Although substantial progress has been made in simulating the physical operation of water resource systems, challenging problems still remain. These consist of multi-objective evaluations of physical output and application of operations research techniques. The application of stochastic theory to water resource systems analysis also remains a challenge, although great progress has been made in recent years. The development of an optimum plan of water resources management will require the integration of objectives such as economic efficiency, environmental protection, ecological management, and social well-being. Application of operations research techniques, such as linear or dynamic programming, has been impeded by the extreme complexity of water resource systems. Nonlinearities and interrelationships that change with time and location make optimization particularly difficult. The most promising approach appears to be the internal analysis of systems that would lead to logical deduction of system outputs from system inputs.

TRANSPORT REPLACEMENT POLICY: STATUS REPORT

The costs of physical distribution, like the costs of production or marketing, consist of a number of elements whose prices are frequently determined independently and without apparent reference to each other. In the same way that production costs can be controlled by varying the inputs of capital, raw materials and labour according to their current cost relationships; or the efficiency of a marketing programme maximised through judicious adjustment of the marketing mix, so can the costs of physical distribution be minimised by scientific warehouse location, inventory control, transport mix analysis, containerisation and route planning. Widespread application of operational research techniques, industrial engineering and marketing research mean that the spectacular savings available in the past in marketing and production have been achieved.

Applications of methods of operations research and modern economic theory

It is rather a pity that we received only three papers especially devoted to subject 2, “applications of methods of operations research and modern economic theory”. Maybe the time for real applications of operations research techniques in the insurance field has still to come. However, I am convinced that sooner or later such techniques—in connection with the use of the computor—will play a more or less important part in the management of insurance business. An impulse to this of course will be the appearance of —let me say—“textbooks” on this subject; such as the book written by Wolff, Methoden der Unternehmensforschung im Versicherungswesen, Springerverlag 1966, a copy of which I received a few days ago.Meanwhile, the fact that only a few papers have been sent in gives me the opportunity to report on them in some detail and to make a few side remarks.The studies presented are:Borch. Dynamic decision problems in an insurance company, de Leve and Weeda. Driving with Markov-programming.d'Hooge, Franckx and Gennart. Utilisation pratique de la méthode de simulation dans l'assurance “non-life”.The paper Prof. Borch submitted, deals essentially with some problems related with random walk theory. Partly it can be considered to be the counterpart of the classical discontinuous ruin theory as its subject is the expected duration of life of the company and maximisation of the discounted value of dividend payments.The question of calculating the expected duration of life and more specially the means the company has to influence its future lifetime involves reinsurance and utility theory to which topic in recent years Prof. Borch has devoted a number of very interesting publications.

Operations Research Approach to the Reciprocal Impact of Transportation and Land Use

Many transportation-land use impact studies of the past have dealt with the micro-details without sufficient reference or understanding of the broader and often more significant influences. It is suggested that the application of operations research techniques may be the best way of determining these significant interactions in our complex society.

Application of Operations-Research Techniques to Airborne Weapon System Planning

It is believed that the extension and application of operations research techniques to systems analysis can improve the basis for decisions on new airborne weapon systems. Although the surface has only been scratched in this field and many things are yet to be learned, experience to date has provided reason for confidence that these methods will prove to be reliable and useful tools for the executive over the years. As experience and know-how increase, and sufficient groups of qualified personnel become available in both industry and the military, such analyses should become recognized as matters of good business procedure. It is to be hoped that in the future standard practice both in industry and in the Department of Defense will require that systems analyses be performed in advance of all basic planning decisions for design and production of future weapon systems. Operations Research, ISSN 0030-364X, was published as Journal of the Operations Research Society of America from 1952 to 1955 under ISSN 0096-3984.