bluuebunny/crossref_metadata_2025 huggingface dataset:
Weighting Multiple Criteria
Authors: Eckenrode Robert T.
Published: November 2008

Six methods for collecting the judgments of experts concerning the relative value of sets of criteria were compared for their reliability and time efficiency. The methods were ranking, rating, three versions of paired comparisons and a method of successive comparisons suggested by Churchman, Ackoff and Arnoff [Churchman, C. W., R. L. Ackoff, E. L. Arnoff. 1957. Introduction to Operations Research. Wiley, New York.]. The judgment situations used were concerned with the design of a specific air defense system and a general air defense system, and with selecting a personnel subsystem manager for a development program. In each of these three situations six criteria were comparatively evaluated by the judges. The results of these experiments showed that there were no significant differences in the sets of criterion weights derived from collecting the judgment data by any of the methods, but that ranking was by far the most efficient method. A fourth experiment was conducted to develop baseline data on the time required to make comparative judgments vs. number of items to be judged, by the ranking method and by the simplest paired comparisons method. Ranking is increasingly more efficient than paired comparisons as the number of items to be judged increases from six to 30.
Optimal Policy for a Multi-Product, Dynamic, Nonstationary Inventory Problem
Authors: Veinott Arthur F.
Published: November 2008

This paper is concerned with a multi-product dynamic nonstationary inventory problem in which the system is reviewed at the beginning of each of a sequence of periods of equal length. The model has the following features. There is a general demand process with no stationarity or independence assumptions, partial or complete backlogging of unfilled demand, a fixed non-negative delivery lag (which may be positive only under complete backlogging), a nonstationary linear ordering cost, a nonstationary holding and shortage cost function, discounting of future costs, and nonstationary restrictions like budget and storage limitations. The objective is to choose an ordering policy that minimizes the expected discounted costs over an infinite time horizon. Conditions are given that ensure that the base stock ordering policy is optimal and that the base stock levels in each period are easy to calculate.
A Dynamic Analysis of a Class of Deteriorating Systems
Authors: Eppen Gary D.
Published: November 2008

This paper considers a model for the maintenance of a deteriorating system with a discrete state space. At discrete points in time a sequence of maintenance decisions is to be made. These decisions are either to leave the system in its present state, or by performing maintenance to place it in a “higher state.” Between maintenance visits the behavior of the system is described by a stationary Markov matrix. For a maintenance cost c·z (where z is the number of states by which the system is improved) and a convex one-period operating cost L(·) a class of transition matrices is found which lead to simple maintenance policies. It is also shown that the restrictions on the transition matrix are not only sufficient but “almost necessary” if the result is to hold for all possible choices of L(·).
On the Theory of Divisional Structures: Some Aspects of Centralization and Decentralization of Control and Decision Making
Authors: Zannetos Zenon S.
Published: November 2008

The organization structure of the firm has been the subject of diverse research approaches. The purpose of this paper is to provide a framework for integrating the various views and analyzing the various factors that affect centralization and decentralization. After a historical review of some milestonee in organization research, a definition of decentralization which is based on the overall objectives of the firm is provided. The notions of hierarchical and mutual interaction structures are examined and contrasted with the notion of decentralization. Finally, the determinants of divisionalization are analyzed, and the suggestion is made that a study of the covariance matrix of subunit performance will guide us to the areas that need attention for possible reorganization.
Intraorganizational Decision Processes Influencing the EDP Staff Budget
Authors: Weber C. Edward
Published: November 2008

The results of a field study were reported, and implications were suggested for a behavioral theory of the firm. The field study focused on several managers whose decision strategies influenced the budgeted size and composition of the staff of an electronic data processing department (EDP). Two of the managers were directly responsible for proposing the salary budget of EDP. Their decisions were influenced by the decisions of other managers, and the decision processes of both those directly involved and those indirectly involved were analyzed. The study showed the constraints entering into the strategies of managers in a specific situation, and the analysis of these strategies suggested how organizational goals were woven into the managers' decisions. In the situation described, at least, there was less bargaining than our hypotheses had led us to expect. There were conflict and “politics,” but they appeared to be due to differences in judgments about goal expectations of superiors.
Balancing Accuracy and Simplicity in Determining Reorder Points
Authors: Hunt Joseph A.
Published: November 2008

Many methods have been developed to determine the proper reorder points and order quantities in an inventory system. These methods are based on a wide range of inventory models—from elementary deterministic models to sophisticated probabilistic models with time-varying parameters. This paper deals with two topics related to these calculations which were encountered during the design of an inventory control system for a firm in the heavy goods industry.

A mathematical model is developed to describe the average annual variable cost of maintaining the inventory. Based on this model, the paper evaluates the savings obtained by using a simultaneous solution for reorder point and order quantity rather than a simpler separate solution. Then, this model is extended to describe the effect of batch withdrawals as a renewal process. The paper presents an adjustment which can be applied to the original reorder points based on unit withdrawals. Both of these topics are described in the context of a practical application.
Dynamic Programming
Authors: Howard Ronald A.
Published: November 2008

Dynamic programming is a mathematical technique for solving certain types of sequential decision problems. We characterize a sequential decision problem as a problem in which a sequence of decisions must be made with each decision affecting future decisions. We need to consider such problems because we rarely encounter an operational situation where the implications of any decision do not extend far into the future. For example, the best way to invest funds this year depends upon how the proceeds from this year's investments can be employed next year. The maintenance policy we should use for our machinery this year depends upon what we intend to do with this machinery in the future. The examples are as numerous as the fields of man's endeavor.
Markovian Decision Models for Reject Allowance Problems
Authors: Klein Morton
Published: November 2008

Most manufacturing processes produce some defective items. To compensate for this, the total quantity produced in attempting to satisfy an order is larger than the order size. The excess is called a reject allowance. In this paper it is shown how the Markovian decision framework can be used to determine the amount to produce when production is, or can be, divided so that the products can be inspected before the production run is ended.
On Jockeying in Queues
Authors: Koenigsberg Ernest
Published: November 2008

There are numerous queueing situations in which those awaiting service may be allowed to make choices which affect the time spent in the service system. In such cases, it should be possible to formulate a “strategy” for customers to follow in order to optimize a given parameter. A whole class of queue problems which involve “jockeying” can be regarded in this way, but has so far received little attention. Jockeying can be described as the movement of of a waiting customer from one queue to another (of shorter length or which appears to be moving faster, etc.) in anticipation of a shorter delay. We have so far considered steady state solutions for just a few of the various possible jockeying disciplines in two-server systems with heterogeneous “exponential” servers and Poisson inputs. As a basis for comparison, we first treat the heterogeneous server problems where arriving customers join the shorter of two independent waiting lines and are not permitted to jockey. The same problem is then considered allowing instantaneous jockeying from the longer to the shorter line when the difference in line lengths exceeds one. The results, in terms of expected line lengths and delays, are identical to those obtained by Gumbel (Gumbel, H. 1960. Waiting lines with heterogeneous servers. Oper. Res. 8 504.) for heterogeneous servers fed from a single queue. When the same problem, with customer preferences for a specific line, is considered the results are identical to those of Krishnamoorthi (Krishnamoorthi, B. 1963. On a poisson queue with two heterogeneous servers. Oper. Res. 11 321). It is important to note that in these two problems the slower server has a larger throughput than might be expected from the classical theory. In other words, the slower server acts as a trapping state. In the last problems treated here, customers join a preferred line and may jockey at a rate proportional to the line lengths or proportional to the difference in line lengths.
Scheduling Independent Tasks on Parallel Processors
Authors: Rothkopf Michael H.
Published: November 2008

This paper considers the problem of scheduling m independent, immediately available tasks on n parallel processors. Each task has a waiting cost rate, that is a function of time, and a service time. There are no feasibility restrictions on the order in which the tasks are to be processed. An optimal scheduling rule is presented for the single processor scheduling of tasks with continuously discounted linear waiting costs. A dynamic programming algorithm has been developed for a wide class of parallel-processor problems. Linear waiting costs (with or without discounting), arbitrary processor use costs, and certain other costs are considered. In certain cases, the service time of a task may be a function of the processor that performs it.
Search-Theoretic Models of Organization Control by Budgeted Multiple Goals
Authors: Charnes A. , Stedry A. C.
Published: November 2008

Models of situations in which individuals are faced with multiple activities among which they must allocate their effort are postulated. Optimal allocations are found for four assumed motivational structures—profit maximization and three involving performance goals in each of the activities. Heuristic approximations to the optimal allocations are developed. Also, the relationships between the various motivation structures are explored.
The Average Investment Performance Index
Authors: Cohen Kalman J. , Fitch Bruce P.
Published: November 2008

In this paper, which is the first step in our efforts to produce an objective standard for use in measuring the investment performance of any portfolio of securities over some period of time, we introduce the average investment performance index (AIPI). The AIPI measures the average return which could have been realized during a particular time period from some specified universe of securities. Our reasons for constructing the AIPI are presented in Section I, where we also formally define the AIPI and discuss the random portfolios which conceptually underlie it. Section II is a mathematical development of the AIPI's properties. We find that the AIPI is equivalent to an unweighted arithmetic average of all actual returns in the given universe of securities, we show how to compute the variance of returns from all possible random portfolios, and we develop a method for linking the values of the AIPI across successive time periods. The use of the AIPI and the variance of random portfolio returns for rating the investment results achieved by portfolio managers is discussed and illustrated in Section III. We feel that the objective evaluations which are the basis of our illustrations should allow the reader to assess the applicability and implications of using the AIPI as a measure of investment performance.
Siting a Distribution Centre, An Analogue Computer Application
Authors: Eilon Samuel , Deziel D. P.
Published: November 2008

This paper describes the use of a general purpose electronic analogue computer for locating a distribution centre, or in general for solving the problem of link-length minimization in networks (for example, when it is required to locate a set of supply points, such that the overall cost of transportation is minimized). Analogue programmes for solving the problem with one or two distribution centres are given and the extension of the method to cover the case of m distribution centres is indicated. Examples for systems with one and two distribution centres are solved and results are compared with those obtained analytically. The method can be extended to cover the case where costs are a non-linear function of distance.
Capital Budgeting of Interrelated Projects: Survey and Synthesis
Authors: Weingartner H. Martin
Published: November 2008

As capital budgeting decision procedures become more complex, they must allow for more aspects of the real world. The present article surveys the techniques available to handle the important and generally neglected problem of project interrelationships such as mutual exclusion and interdependencies. The techniques utilized are linear and integer programming, dynamic programing, and the discrete optimizing procedure of Reiter. Project interrelationships arising from randomness of outcomes and nonlinear utility functions are also subjected to scrutiny by application of these procedures, and additional interrelationships, arising in the context of research and development budgets, are analyzed. A dynamic programming code for the multidimensional 0-1 knapsack problem is also presented.
Scheduling Short-Run Changes in Production to Minimize Long-Run Expected Costs
Authors: Kunreuther Howard
Published: November 2008

This paper investigates the problem of scheduling production from one period to the next to minimize long-run expected costs where the only relevant considerations are the expense of revising production and the charges related to inventory. We first consider the case of constant sales known over time in order to compare exact and approximate solutions. The approach to these solutions is based on minimizing the costs of deviating from long-run equilibrium values of production and inventory. The same approach is then used to handle the more realistic possibility of uncertain future demands. Solutions are obtained for both linear and quadratic inventory and production cost functions. Because future demand is assumed to be specified by some probability distribution, inventory costs must be approximated in order to obtain a closed-form solution; however, the result should differ insignificantly from an exact optimal solution.
The Dual Method for the Generalized Transportation Problem
Authors: Balas Egon
Published: November 2008

In this paper the dual method and the poly-ω technique are specialized for the generalized transportation problem. A simple procedure is obtained for solving the parametric version of this problem, i.e. for passing from a solution optimal for given values of the parameters, to solutions optimal for other values of the parameters. This procedure is then extended to the case when not only the parameters change, but additional constraints appear. Finally, the procedure may be used as a general method for solving the usual (nonparametric) generalized transportation problem, and for this case a way is described for finding an initial (dual-feasible) solution.
On the Efficient Use of High Aswan Dam for Hydropower and Irrigation
Authors: Thomas Harold A. , Revelle Roger
Published: November 2008

With, the completion of the High Aswan Dam it will be possible to use the water of the Nile River in many different ways for different beneficial purposes. The selection of the best method of operating the dam and developing new resources to speed economic growth and social progress is of great importance to the United Arab Republic. A large sustained multidisciplinary effort combining economic analysis, engineering design, and governmental planning will be required. It is the purpose of this paper to describe some analytical methods that will be useful in this undertaking. A mathematical model for computer studies is developed to elucidate and quantify the relations between the variables pertaining to agricultural and power uses. Other functions of the dam such as flood protection and improvement of navigation are not examined in this initial study. However, it will be possible to investigate them in a more comprehensive model using similar mathematical methods. In its present form the model is designed to use standard linear programs so that operations studies can be made without recourse to sophisticated computer techniques. The model incorporates some of the chief factors affecting efficiency of multipurpose operation for the generation of hydroelectric power and for increasing the agricultural production of the United Arab Republic. The formulation provides a logical framework on which other functions may be added at a later stage. In the last section of this paper some of the most important modifications and elaborations are discussed.

The numerical data used in the present study are based on a preliminary analysis of available hydrological and economic data. Considerably more statistical analysis will be required to develop valid numerical data for the model so that reliable inferences and rational decisions can be made. The computational results at this stage are useful only in indicating the kind of inferences and the type of information that may be obtained in a more definitive study.
Uncertainty and its Effect on Capital Investment Analysis
Authors: Solomon Martin B.
Published: November 2008

When uncertainty concerning costs, revenues, and project life exists, classical measures of capital investment return are limited in value. Sensitivity analysis indicates that relatively small over estimates and under estimates create relatively large errors in the discounted rate of return for different types of return schedules. Perhaps, then, businessmen are justified in seeking other methods of project evaluation.
A Chance-Constrained Model for Real-Time Control in Research and Development Management
Authors: Charnes A. , Stedry A. C.
Published: November 2008

Funding of research projects is considered as encompassing three stages: (1) an initial short run plan for funding based upon projected regular demands and availability subject to random deviations; (2) adjustment of the initial plan to take into account the actual regular demands and availability and the funding of significant break-throughs which occur at random intervals preempting other demands; and (3) a plan for longer-run availability and demands which constitute a “posture” desired subsequent to the funding adjustments of (2). The essence of the distribution of the unexpected demands is multi-modality with low probability of occurrence but high resource demand when they do occur. This approach represents a substantial departure from the usual planning model development which produces only an optimal plan based on forecasted developments without provision for adjustment when the forecasted events actually materialize and additional unexpected demands are placed on resources. The adjustment process explored here—which provides the mechanism for optimal implementation of the original plan or control of resource allocation-enables optimal response to information received in “real-time” avoiding the frequently observed over- or under-response to receipt of such information without reference to the impact of the interim decision on future capabilities.
Scheduling with Random Service Times
Authors: Rothkopf Michael H.
Published: November 2008

This paper considers the problem scheduling of m immediately available tasks with random variable service times. It is shown that certain such problems can be reduced to equivalent deterministic problems. The existence of optimal schedules not involving the removal from service of incompletely processed tasks for some problems is proved and for other problems is disproved.
Optimal Search for a Maximum with Sequences of Simultaneous Function Evaluations
Authors: Avriel Mordecai , Wilde Douglass J.
Published: November 2008

A minimax search plan is developed for locating the maximum of a unimodal function of one variable with a sequence of blocks of simultaneous function evaluations. The proposed “block search strategy” is described for any number of simultaneous function evaluations (experiments) and for any number of blocks in the sequence. For one experiment per block it reduces to the Fibonacci strategy; in the case of only one block of experiments, to the simultaneous search plan. The “block search strategy” is optimal in the sense that for a required final interval of uncertainty, known to contain the point where the function attains its maximum, and for any given number of simultaneous experiments and blocks, it has the largest possible starting interval. A discrete variable version of the proposed search strategy is also described.
Matrix Rounding Problems
Authors: Bacharach Michael
Published: November 2008

The problem considered in this paper is that of consistently rounding off the elements of a matrix and its row and column sums. It is shown that a class of rounding problems of this kind is equivalent to a class of problems of determining flows through networks having arbitrary lower as well as upper bounds on edge flows. An existence theorem first proved by Hoffman for flows in such networks is used to show that an important subclass of the matrix rounding problems considered is always soluble. An algorithm for the entire class is illustrated by a numerical example.
Factors Influencing Market Penetration
Authors: Allen R. W.
Published: November 2008

The decision of a company in the selection of a technological business area to exploit is a difficult one to make because of the many complex factors involved and the uncertainties of predicting future events. To assist the management decision processes, a mathematical model is developed which relates the many factors such as company capability, time, market, competition, investment and costs to the expected economic gain over time. The basis of the model presupposes that the markets of interest are composed of many product areas in which companies will compete for a share. Thus, the model is concerned with two opposing forces (competition versus the company) trying to penetrate the same available product area simultaneously over a given time period. In addition to the model formulation several basic types of markets are analyzed as to their effect on the various economic factors. Also, the effect of the investment program in the market penetration is exhibited as well as the effect of loss in market shares on the maximum economic gain.
Quadratic Assignment Problem Algorithms and the Location of Indivisible Facilities
Authors: Hillier Frederick S. , Connors Michael M.
Published: November 2008

This paper discusses the problem of assigning locations to indivisible facilities and its relation to the quadratic assignment problem. It also develops two suboptimal algorithms, one dealing with the general quadratic assignment problem and the other with an interesting special case. Qualitative and quantitative comparisons with existing suboptimal algorithms are presented.
An Improved Starting Algorithm for the Ford-Fulkerson Approach to the Transportation Problem
Authors: Mueller-Merbach Heiner
Published: November 2008

This paper presents an algorithm for yielding an improved initial dual solution of the transportation problem when the network flow algorithm of Ford and Fulkerson is used. (1) The algorithm is described. (2) It is demonstrated by means of a numerical example. (3) Computational experience is reported. 400 medium-sized (30 × 80; 50 × 60; 50 × 80) test problems with three different kinds of distance matrices and two different kinds of shipment quantity vectors were evaluated. The average improvement over the usual method was about 30%.
An Investigation of Design Methodology
Authors: Nadler Gerald
Published: November 2008

A methodology other than that used for research may be more appropriate for designing and engineering projects. This paper compares the purposes and methodologies of research and of designing, and concludes that while their purposes are different, their current methodologies are the same.

The research or scientific methodology—with analysis as its hallmark—is shown to restrict the effectiveness of a design solution. To achieve an effective design solution, a methodology distinctly different from the research methodology is required.

This paper reports on research which attempted to delineate the actual strategies used by outstanding professionals in various fields. It was found that such experts, although in different fields, have strong similarities in the steps of the strategy each used.

The applications of an empirical ten-step design strategy with function determination and ideal systems development as hallmarks have shown much better results than conventional strategies based on the research methodology.

Additional research is suggested to verify these early conclusions and to make the stated design strategy more effective.
Simulating Communication Network Experiments
Authors: Marshall Wayne S.
Published: November 2008

A report of a computer simulation of human behavior in Bavelas-type communication network experiments. The simulation successfully imitates behavior in the five-man chain network, and does reasonably well for a six-man Y net, but fails on a more complex six-man net. Main features of the simulation are described. In order to simulate human behavior, a number of non-optimal activities were initially permitted in the simulation and were discarded gradually by probabilistic selection of “desirable” patterns of message sending. Results lead one to question the notion of “optimal performance,” even for a simple communication task in a small group.
Basic Concepts for a Theory of Organization
Authors: Stogdill Ralph M.
Published: November 2008

Classical and behavioral theories can be reconciled if organization is regarded as an input-processing-output system. If material and financial resources are disregarded, all organizations utilize human performances, expectations, and interactions as inputs. In newly formed groups and organizations, these three variables act upon each other to generate structure, operations, and interpersonnel. The latter three variables, once they become differentiated and are utilized in task performance, act as processors to transform the inputs further into product, drive, and cohesiveness as outputs. The hypothesized relationships between the output variables are in accord with research findings and reconcile long standing discrepancies.
A Computer Simulation Model of Municipal Budgeting
Authors: Crecine John P.
Published: November 2008

An increasing awareness of the importance of urban governmental activities draws attention to municipal expenditures and to the municipal operating budget. Little effort has been directed toward the question of how municipalities allocate resources. The work reported here represents an attempt to develop a positive theory of municipal resource allocation for large metropolitan communities and to subject this theory to empirical tests. Cleveland, Detroit, and Pittsburgh are used as data points.
Exponential Smoothing and Short-Term Sales Forecasting
Authors: Harrison P. J.
Published: November 2008

Non-seasonal forecasting methods are examined by considering demand generating processes which are reasonable and general descriptions of customer demand and for which the popular predictors are shown to be optimal. Tests of the adequacy of the generating processes are described. The way in which the forecasting errors vary with the forecasting period is examined, and it is shown that this is dependent not only on the length of the period but also on the values of the forecasting parameters. The sensitivity of the predictors to departures from the optimal parameters is investigated, and the long debated comparison of Holt's linear growth predictor (1957) and Brown's linear growth predictor (1959) is examined. It is shown for the assumed generating model and for forecasting parameters lying within the usual limits, that even if there is an infinite amount of data available to establish the optimum forecasting parameters, the standard error of the one step ahead predictor exceeds that of the Holt predictor by no more than 1.6 percent. The generalized polynomial generating process is shown to have as its optimal least squares predictor the corresponding Box-Jenkins polynomial predictor (1962).
Randomized Replacement Rules which Maximize the Expected Cycle Length of Equipment Subject to Markovian Deterioration
Authors: Kolesar Peter
Published: November 2008

A problem of determining the form of optimal replacement policies is treated. Equipment whose changes of state can be described by a finite Markov chain are considered. The objective of the replacement policy is the maximization of the expected time between replacements while keeping the probabilty of an in-service failure below a specified bound. It is shown that, if the equipment “ages,” a replacement policy of simple structure called a randomized control limit rule will be optimal. Such a policy can be determined by linear programming.
Integer Programming Formulation of Constrained Reliability Problems
Authors: Tillman F. A. , Liittschwager J. M.
Published: November 2008

This paper investigates the solution by integer programming of reliability optimization problems which are subject to linear and nonlinear separable restraints. In particular, the following problems are solved:

(1) maximizing reliability for a parallel redundancy system subject to multiple linear restraints,

(2) minimizing cost of a parallel redundancy system subject to multiple nonlinear and separable restraint functions while maintaining an acceptable level of reliability,

(3) optimal choice of design for a parallel redundancy system.

Also discussed are the necessary alterations to the above formulations for problems involving standby redundant units.
The Piecewise Concave Function
Authors: Zangwill Willard I.
Published: November 2008

An important function which is neither concave nor convex often arises in production and inventory models. This function is herein called piecewise concave and can be considered to be a generalization of the concave function. Essentially it is the maximum of a collection of concave functions. Various properties of piecewise concave functions are explored in this paper. In particular, a theory is developed to locate the point at which such functions are minimized. A short discussion of applications is included.
Least Squares Fit of Definite Quadratic Forms by Convex Programming
Authors: Hartley H. O. , Hocking R. R. , Cooke W. P.
Published: November 2008

This paper considers the problem of fitting a quadratic regression law subject to the condition that the fitted surface be convex (concave). A computational algorithm is described for determining the constrained regression coefficients using an existing non-linear programming algorithm. Some of the properties of the estimators are described.
Toward Better Curricula Through Computer Selected Sequencing of Subject Matter
Authors: Taft Martin Israel , Reisman Arnold
Published: November 2008

It is generally recognized that reinforcement, over an extended period of time of a given subject matter taught, enhances the student's mastery and subsequent retention of knowledge and/or skills. Recent major studies of curricula have concentrated on the content and method of presentation but have not made any significant strides towards the systematic exploitation of the potential contribution to the learning process of reinforcement through proper sequencing of subject matter presentation. This paper outlines a mathematical model of the established and industrially validated learning and forgetting theories and presents a computer executed heuristic algorithm for the selection of the best schedule for subject presentation. Applications of this methodology can be made at all levels of our educational system; from the elementary grades through graduate school, in highly academic as well as vocational training programs.
A Review of Buyer Behavior
Authors: Sheth Jagdish N.
Published: November 2008

Post-war advances in technology have changed the concept of marketing management considerably. The core of this change is the shift of emphasis from the firm to the buyer. In this survey article, the author reviews all the important approaches to understanding buying behavior and provides an up-to-date bibliography.

Two important issues emerge from the review. First, the existing variety of formulations resembles the variety of responses of seven blind men touching different parts of an elephant and making inferences about the animal which necessarily differ from, and occasionally contradict, one another. Second, the theory which attempts to explain the observed phenomenon of buying behavior and the quantitative techniques which provide adequate definitions and measurements have been developed independently of each other to the detriment of the maturity of the discipline.
Measurement Problems in Cluster Analysis
Authors: Morrison Donald G.
Published: November 2008

In the first part of this paper we will review and modify the cluster analysis procedure presented by Green, Frank and Robinson [Green, P. E., R. E. Frank, P. J. Robinson. 1967. Cluster analysis in test market selection. Management Sci. 13 (8, April) B-387–B-400.] in a recent issue of this journal. In revising their procedure, we will raise some very fundamental questions with respect to cluster analysis in particular and multivariate statistics in general. The scale that we use in measuring the input variables (e.g., age, income, education, etc.) will affect the results. The question is: “How do we scale the input variables so that the results are ‘meaningful’?” We will see that some of the usual methods that are used to give statistically meaningful results will not assure us of managerially meaningful results. Finally, a possible “solution” along with its advantages and disadvantages over standard techniques will be presented.
Dynamic Job Assignment for Railway Personnel
Authors: Pappás Ioánnis A.
Published: November 2008

This paper presents the results of a study on the assignment of jobs to the travelling personnel of a small railway company.

The jobs in question are those of engine driver, conductor, etc. On one hand, these jobs have different requirements; on the other, the employees have different qualifications. The problem is to match job requirements and employee qualifications. The problem is a dynamic one since employees are assigned jobs on consecutive days of the month and, at the same time, a number of constraints as to the succession of jobs assigned to an employee are to be respected. In addition, all employees should get their fair share of jobs of each kind, early and late ones, short and long ones.

This job assignment planning was formerly done in the company by means of a planning board every month—a procedure which was time-consuming and did not distribute the jobs among the employees fairly enough. A computer solution was, therefore, called for which would reduce the planning cost and also give greater employee satisfaction—an important factor in these days of “overemployment” and increasing demand for more leisure time.
Load Forecasting, Priority Sequencing, and Simulation in a Job Shop Control System
Authors: Bulkin Michael H. , Colley John L. , Steinhoff Harry W.
Published: November 2008

This paper reports the development, installation and evaluation of a simulation which sequences shop operations for the next shift. Simulation outputs give each foreman the priority of jobs currently in his section and those jobs which might be coming through his area during the next work period. The foreman can determine in advance what tools, raw materials, etc., are needed and obtain them, thus tending to eliminate queue time for hot jobs.

In three months of operation, the simulation has been more successful than initially expected. Coordination and expediting efforts have been reduced, in-process inventory has been reduced along with worker idle time, and schedule performance has improved. An additional important result noted during this time is an enlargement of the foreman's job. He has less need for coordinators and expediters since he has the information needed to make rational decisions on sequencing the work.

This effort illustrates the practicality and desirability of incorporating advanced concepts into operating systems if the system's demands on working personnel are made compatible with the objectives and capabilities of the workers.
Scheduling Maintenance and Determining Crew Size for Stochastically Failing Equipment
Authors: Vergin R. C.
Published: November 2008

Past treatment of the single machine maintenance problem has shown that preventive maintenance may be desirable for equipment for which failures are caused at least partially by wear-out factors. In all previous treatment, however, the size of the maintenance-repair crew has been held constant and the optimal maintenance period has then been determined. This paper develops a simultaneous solution for the maintenance-repair crew size and the optimal maintenance period. The optimal maintenance period is seen to shift as the size of the maintenance-repair crew varies.

For the multi-machine maintenance problem, the sharing of the maintenance-repair crew creates a queuing system. Because of its complexity, an analytical solution of this multi-machine maintenance queuing system is not feasible. A simulation model was used to develop a set of general rules for scheduling maintenance for the multi-machine case.
Discrete Optimization Via Marginal Analysis
Authors: Fox Bennett
Published: November 2008

Discrete optimization subject to one constraint is attacked by Lagrangian analysis. Incremental allocation schemes are given that generate undominated allocations. In an important special case, the complete family of undominated allocations is generated.
An Engineering Approach to the Traveling Salesman Problem
Authors: Roberts S. M. , Flores Benito
Published: November 2008

An engineering approach to the traveling salesman problem is a method which is intuitively “reasonable” to the non-mathematician. It consists of a sequence of operations which (1) develops good starting circuits, (2) improves these circuits, (3) extracts sufficient information from the improved circuits to determine pairs or chains of cities likely to appear in the conjectured global minimum cost circuit, (4) with certain cities paired off, develops the graph of the network. The graph program generates all the circuits from the smallest to the largest cost. The method has been applied successfully to the 20, 48, and 57 city traveling salesman problems.
Models and Modelling for Manpower Planning
Authors: Dill W. R. , Gaver D. P. , Weber W. L.
Published: November 2008

Some parts of the long-range planning problem have been widely discussed. Other parts have received less attention. Of the relatively neglected areas, one of special importance is manpower planning. Manpower planning includes a specification of the kinds and numbers of men an organization will need to accomplish its profit, growth, or service objectives; a forecast from current personnel inventories of how well it is now set to meet the projected needs; and by a comparison of needs with forecasted supply, the formulation of plans for recruiting, assigning, and developing personnel.

This paper explores some issues in manpower planning. We review some of the kinds of approaches that have been tried and look in some detail at two approaches which seem especially promising.
Regression Yield Curves for U.S. Government Securities
Authors: Cohen Kalman J. , Kramer Robert L. , Waugh W. Howard
Published: November 2008

The uses of regression analysis to estimate market yield curves for U.S. Government securities are considered in this paper. Several possible regression models for this purpose are examined. It is found that models which regress either the before-tax yield or the after-tax yield of governments on the number of days remaining to maturity and the square of the logarithm of the number of days remaining to maturity can fruitfully be applied to actual market data in determining yield curves.
Optimum Seeking with Branch and Bound
Authors: Agin Norman
Published: November 2008

A wide variety of branch and bound algorithms have recently been described in the literature. This paper provides a generalized description of such algorithms. An objective is to demonstrate the wide applicability of branch and bound to combinatorial problems in general. Two existing algorithms are used as illustrations and a discussion of computational efficiency is included.
Non-Linear Programming Via Penalty Functions
Authors: Zangwill Willard I.
Published: November 2008

The non-linear programming problem seeks to maximize a function f(x) where the n component vector x must satisfy certain constraints gi(x) = 0, i = 1, …, m1 and gi(z) ≧ 0, i = m1 + 1, …, m. The algorithm presented in this paper solves the non-linear programming problem by transforming it into a sequence of unconstrained maximization problems. Essentially, a penalty is imposed whenever x does not satisfy the constraints. Although the algorithm appears most useful in the concave case, the convergence proof holds for non-concave functions as well. The algorithm is especially interesting in the concave case because the programming problem reduces to a single unconstrained maximization problem or, at most, to a finite sequence of unconstrained maximization problems. In addition, the paper presents a new class of dual problems, and the algorithm is shown to be a dual feasible method. Another property of the algorithm is that it appears particularly well suited for large-scale problems with a sizable number of constraints.
An Algorithm and Computational Procedure for Locating Economic Facilities
Authors: Vergin Roger C. , Rogers Jack D.
Published: November 2008

The problem of locating economic facilities in such a manner as to minimize the cost of moving inputs from source points to the facilities and outputs from the facilities to subsequent destination points has had considerable attention in recent times. A wide and diverse variety of approaches which give reasonable but not necessarily optimal solutions to such problems has been suggested. This paper suggests a different approach to this familiar problem. For a single facility location problem, an algorithm is presented which produces optimal locations. For the case of locating several new facilities a computer search process is instituted which produces close to optimal locations.
The Evaluation of Potential New Product Alternatives
Authors: Freimer Marshall , Simon Leonard S.
Published: November 2008

In evaluating new product opportunities through the use of a rating scheme, account must be taken of the fact that the individual factors on which the product is being assessed interact in producing an overall result. A score for a product may be thought of as a point in n dimensional space in which are located two density functions, one representing scores of successful products and the other of unsuccessful products. Linear discriminant analysis provides the means for utilizing the likelihood ratio of success to failure for any given potential product (point). The question then arises as to whether to accept the decision dictated by the discriminant analysis or to collect more information concerning the location of the point. Both a posterior and a preposterior distribution can be obtained, yielding the value of additional information and thus determining whether to make the decision now or to postpone it.
Management Science in the World of Today and Tomorrow
Authors: Dantzig George B.
Published: November 2008

Operations Research or Management Science, two names for the same thing, refers to the science of decision and its application. In its broad sense, the word “cybernetics,” the science of control, may be used in its place. This science is directed towards those tasks that humans have not yet delegated to machines. Tasks involving human energy and (as we have seen) those involving simple human control have already been conceded to machines even though they have not been fully taken over by them. It is the automation of higher order human decision processes that is the last citadel.
The Queue M/G/1 With Feedback to Lower Priority Queues
Authors: Schrage L. E.
Published: November 2008

The queue M/G/1 with a round-robin type queueing discipline is considered. The overall processing time of a job is assumed to consist of a sequence of “simple” processing times. There are a countably infinite number of waiting queues, 1,2,…, but a single processing facility. A job upon arrival enters the first, or highest priority waiting queue. When a job in the nth queue gains the processor, it receives its nth simple processing time in an uninterrupted fashion and then either departs or enters the n + 1st queue. The processor upon completion of a simple processing time selects the job to be next processed from the highest priority (lowest index number) non-empty queue. Laplace transforms and expressions for the moments of the time in system distributions are obtained.
Optimality and Computation of (σ, S) Policies in the Multi-Item Infinite Horizon Inventory Problem
Authors: Johnson Ellis L.
Published: November 2008

A multi-item inventory system with periodic review, single set-up cost K plus linear ordering cost c for changing stock levels, and holding and shortage cost l(x) for being in stock position x at the beginning of a period is considered. Demand in any period is assumed to be ξ with probability ϕ(x,ξ), where x is the stock level at the beginning of the period. The infinite horizon optimum policies found consist of ordering up to S for any point x in σ, the reorder region, and not ordering at x not in σ. A computational procedure is given, bounds are derived, and, for further assumptions on l, σ is further characterized.
Optimal Timing of Bond Refunding
Authors: Weingartner H. Martin
Published: November 2008

Refunding is the operation by which the issuer of a bond calls it before maturity in order to replace it with another issue. The chief reason for calling is the interest saving which a new bond may make possible. In deciding whether to call a bond at any given time, the issuer must consider not only the potential savings from the current refunding, but also from future refundings up to some horizon fixed by financial policy. These savings must also be compared with those resulting from the decision to postpone refunding. This paper formulates the refunding problem in terms of a dynamic programming model in which the term structure of interest rates is utilized to obtain information about the future course of interest rates.