bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Accuracy of the Simple Peak Hour Approximation for Markovian Queues
Authors: Green Linda V. , Kolesar Peter J.
Published: November 2008

We empirically explore the accuracy of the simple stationary peak hour approximation (SPHA) for estimating peak hour performance in multiserver queuing systems with exponential service times and periodic (sinusoidal) Poisson arrival processes. We show that the SPHA is very good for a range of parameter values corresponding to a reasonably broad spectrum of real systems. However, we do find and document that there are many situations in which this approximation will be very inaccurate.

We postulate and then support empirically a set of hypotheses that link the accuracy of the SPHA and the related point-wise stationary approximation (PSA) to key parameter values and model characteristics. We also present results on the time-dependent behavior of these systems as a function of key parameters.

Finally we present results which indicate that our findings, developed for models with sinusoidal input streams, may apply to a much broader range of Markovian models with more general cyclic inputs.
Convergence of Subdifferentials Under Strong Stochastic Convexity
Authors: Robinson Stephen M.
Published: November 2008

We show that if a sequence of random functions satisfies strong stochastic convexity with respect to a parameter, and if the sequence converges pointwise with probability one, then any sequence of elements extracted from the subdifferentials of the functions in the sequence will converge to the subdifferential of the limiting function, again with probability one. This result holds with no differentiability assumption on the limiting function, and even if the limiting function is itself random. It thus extends earlier work, in particular results by Glynn and by Hu. One application is in proving an extended form of strong consistency for infinitesimal perturbation analysis (IPA) when suitable convexity properties hold.
A Note on Evaluating the Overflow Probability Using the Infinite Queue
Authors: Avi-Itzhak Benjamin , Halfin Shlomo
Published: November 2008

This note evaluates the approximation of overflow probability put forward by Sakasegawa et al (in a paper published recently in Management Science [5]), and its level of accuracy when applied to traffic generated by bursty sources.
A Note on Application of SD Rules to the Selection of Parameter Estimators
Authors: Zaras Kazimierz
Published: November 2008

This note corrects an error in Levy (Levy, H. 1992. Stochastic dominance and expected utility: Survey and analysis. Management Sci. 38 555–592.) and Ben Horim and Levy (Ben Horim, M., H. Levy. 1982. Evaluating estimators using stochastic dominance rules: The variance of a normal distribution. Comm. Statist.-Theory, Meth. 11(9) 1071–1076.).
Minimizing Single-Machine Completion Time Variance
Authors: Ventura Jose A. , Weng Michael X.
Published: November 2008

In this article the problem of minimizing the completion time variance in n-job, single-machine scheduling is considered. The release times for all jobs are assumed to be zero. A new quadratic integer programming formulation is introduced. A Lagrangian relaxation (LR) procedure is developed to find a lower bound (LB) to the optimal objective value. When the number of jobs is between 100 and 500, our computational study shows that the lower bounds obtained by the LR procedure are very close to the best known objective values. A new heuristic algorithm is also described. The first phase of the heuristic algorithm is a construction procedure whose purpose is to identify a good initial sequence. The second phase is an improvement procedure based on pairwise interchanges. The new heuristic algorithm provides improved solutions compared to the best known heuristic.
A Note on Testing for Skewness Persistence
Authors: Nath Ravinder
Published: November 2008

This paper shows that the tests of skewness persistence considered by Muralidhar (Muralidhar, K. 1993. The bootstrap approach for testing skewness persistence. Management Sci. 39 487–491.) far exceed the true Type I error. That is, the probabilities of detecting an increase (decrease) in skewness from one time period to another when in fact there is no change are inflated. Consequently, higher power achieved by these tests comes at the cost of a higher than specified level of Type I error. We propose a new test which maintains the specified Type I error levels. Additionally, the power of this test for lognormal distributions is reported.
A Note on Strategic Sampling in Agencies
Authors: Bushman Robert , Kanodia Chandra
Published: November 2008

This paper studies sample design for process control in principal-agent settings where deterrence rather than ex post detection is the main issue. We show how the magnitude of gains from additional sampling can be calculated and traded off against sampling costs. It is shown that the optimal sample size shrinks as target rates are lowered.
Decision Roll and Horizon Roll Processes in Infinite Horizon Discounted Markov Decision Processes
Authors: White D. J.
Published: November 2008

In this paper we look at some aspects of infinite horizon Markov decision processes in which information regarding parameter values is restricted to a finite time horizon, and in which decisions are based upon the finite horizon data but are recomputed as we move forward in time and gain knowledge of later parametric values. A general framework is given. Bounds on the loss of optimality arising from two planning horizon decision processes are given, and the choice of decision process and planning horizon is examined.
Server Staffing to Meet Time-Varying Demand
Authors: Jennings Otis B. , Mandelbaum Avishai , Massey William A. , Whitt Ward
Published: November 2008

We consider a multiserver service system with general nonstationary arrival and service-time processes in which s(t), the number of servers as a function of time, needs to be selected to meet projected loads. We try to choose s(t) so that the probability of a delay (before beginning service) hits or falls just below a target probability at all times. We develop an approximate procedure based on a time-dependent normal distribution, where the mean and variance are determined by infinite-server approximations. We demonstrate that this approximation is effective by making comparisons with the exact numerical solution of the Markovian Mt/M/st model.
Two Models for Assessing a Federal Environmental Health Policy: The Case of Radon in U.S. Homes
Authors: Peterson Michael D.
Published: November 2008

The U.S. Environmental Protection Agency's (EPA's) strategy for reducing the public health risks of radon exposure depends largely on convincing the public to undertake testing and mitigation. In this context, important questions arise as to whether public response is likely to be high and thus whether changes in mortality are likely to be substantial. To explore these questions, we develop two models of the “demographics” of radon exposure in the United States. The first of these explores the sensitivity of projected mortality over the next 100 years to important policy variables such as testing and mitigation rates. The second model takes the analysis down to the level of the individual and estimates the distribution of risk across the population and the costs and benefits of mitigation accruing to a person who may change residence several times during his or her life. Our results show that realistic policy scenarios lead to moderate changes in mortality and that the cost-benefit calculation of the individual is unlikely to lead to high levels of public response. The results support the idea of a more focused public policy.
Heuristics for Multimachine Scheduling Problems with Earliness and Tardiness Costs
Authors: Federgruen A. , Mosheiov G.
Published: November 2008

We consider multimachine scheduling problems with earliness and tardiness costs. We first, analyze problems in which the cost of a job is given by a general nondecreasing, convex function F of the absolute deviation of its completion time from a (common) unrestrictive due-date, and the objective is to minimize the sum of the costs incurred for all N jobs. (A special case to which considerable attention is given is the completion time variance problem.)

We derive an easily computable lower bound for the minimum cost value and a simple “Alternating Schedule” heuristic, both of which are computable in O(N log N) time. Under mild technical conditions with respect to F, we show that the worst case optimality (accuracy) gap of the heuristic (lower bound) is bounded by a constant as well as by a simple function of a single measure of the dispersion among the processing times. We also show that the heuristic (bound) is asymptotically optimal (accurate) and characterize the convergence rate as O(N−2) under very general conditions with respect to the function F. In addition, we report on a numerical study showing that the average gap is less than 1% even for problems with 30 jobs, and that it falls below 0.1% for problems with 90 or more jobs. This study also establishes that the empirical gap is almost perfectly proportional with N−2, as verified by a regression analysis.

Finally, we generalize the heuristic to settings with a possibly restrictive due date and general asymmetric, and possibly nonconvex, earliness and tardiness cost functions and demonstrate its excellent performance via a second numerical study.
A Dual Ascent Procedure for Multiproduct Dynamic Demand Coordinated Replenishment with Backlogging
Authors: Robinson E. Powell , Gao Li-Lian
Published: November 2008

This paper describes a mixed-integer programming formulation and dual ascent based branch-and-bound algorithm for the multiproduct dynamic demand coordinated replenishment problem with backlogging. The single sourcing properties of the formulation and the hierarchical structure of the fixed-charge and continuous variables yield an extremely tight linear programming relaxation for the problem. A branch-and-bound algorithm based on Erlenkotter's dual ascent, dual adjustment, and primal construction concepts exploits these properties to obtain an efficient solution procedure. Computational results indicate that the new procedures find optimal solutions in less than five percent of the computational time of the most efficient previous algorithm. The heuristic performance of the procedures also demonstrate their superiority over existing approaches. We solved problems with 12 time periods and 20 products in 0.41 CPU seconds, and heuristic solutions with a worst-case three-percent optimality gap are found in 0.068 CPU seconds. The efficiency and large-scale capability of the procedures make their potential application in inventory requirements planning systems promising.
Context and Antecedents of Information Utility at the R&D/Marketing Interface
Authors: Moenaert Rudy K. , Souder William E.
Published: November 2008

The objective of the present study was to develop a comprehensive empirically-based model of the communication interface between R&D and marketing. Following Moenaert and Souder (Moenaert, R. K., Souder, W. E. 1990. An analysis of the use of extra-functional information by marketing and R&D personnel review and model. Product Innovation Management 7(3, September) 213–229.), a causal model of the antecedents of information utility at the R&D/marketing-interface was postulated. A non-experimental critical incident method was used to test the model. The field survey involved 386 team members of 80 new product innovation teams in 40 companies. Path analysis was used to test the causal model. Support for several aspects of the model were found. First, the relevance and the credibility of the message had strong effects on the perception of information utility. The comprehensibility of the message had a moderate effect on the perception of information utility, whereas novelty had a small effect. Second, the quality of the relationship, the seniority and the prior experience of the message source, and the type of communication channel used had significant effects on the perception of the message. The implications of the research results for managers and researchers are detailed.
Bottleneck Resource Allocation in Manufacturing
Authors: Balakrishan Anantaram , Francis Richard L. , Grotzinger Stephen J.
Published: November 2008

Many resource-allocation problems in manufacturing and service operations require selecting integer-valued levels for various activities that consume “nondecreasing amounts” of limited resources. System productivity, to be maximized, is limited by the least productive (bottleneck) activity. We first review a basic bisection method that can solve this discrete, monotonic resource-allocation problem even with a nonlinear objective and constraints. We then generalize the basic algorithm to solve an enhanced version of the problem containing additional coupling constraints on the allocation decisions. This generalization applies to assembly-release planning (ARP) in a multiproduct assemble-to-forecast environment with part commonality. The ARP problem requires deciding the number of kits for each product to release for assembly in every time period, using the available parts, to achieve if possible the target service levels for all products and time periods or minimize the maximum deviation of the actual service levels from the targets. We also consider extensions of the ARP model incorporating precedence constraints and part substitutability, and show how to modify the bisection method to solve these problems.
The Dynamic and Stochastic Knapsack Problem with Deadlines
Authors: Papastavrou Jason D. , Rajagopalan Srikanth , Kleywegt Anton J.
Published: November 2008

In this paper a dynamic and stochastic model of the well-known knapsack problem is developed and analyzed. The problem is motivated by a wide variety of real-world applications. Objects of random weight and reward arrive according to a stochastic process in time. The weights and rewards associated with the objects are distributed according to a known probability distribution. Each object can either be accepted to be loaded into the knapsack, of known weight capacity, or be rejected. The objective is to determine the optimal policy for loading the knapsack within a fixed time horizon so as to maximize the expected accumulated reward. The optimal decision rules are derived and are shown to exhibit surprising behavior in some cases. It is also shown that if the distribution of the weights is concave, then the decision rules behave according to intuition.
Selling Procedures with Private Information and Common Values
Authors: Lindsey John H. , Samuelson William , Zeckhauser Richard
Published: November 2008

The seller posted-price procedure is probably the most common method for making transactions in modern economies. We analyze the performance of posted pricing for transactions having significant common-value elements. In a model of two-sided private information, we characterize the fully revealing, perfect equilibrium offer strategy of the seller. We also characterize equilibrium behavior under two other pricing procedures—a sealed-bid procedure and a direct revelation mechanism. Finally, we examine the efficiency of these procedures and show that as the degree of common values increases, fewer mutually beneficial agreements are attained.
Estimating Security Price Derivatives Using Simulation
Authors: Broadie Mark , Glasserman Paul
Published: November 2008

Simulation has proved to be a valuable tool for estimating security prices for which simple closed form solutions do not exist. In this paper we present two direct methods, a pathwise method and a likelihood ratio method, for estimating derivatives of security prices using simulation. With the direct methods, the information from a single simulation can be used to estimate multiple derivatives along with a security's price. The main advantage of the direct methods over resimulation is increased computational speed. Another advantage is that the direct methods give unbiased estimates of derivatives, whereas the estimates obtained by resimulation are biased. Computational results are given for both direct methods, and comparisons are made to the standard method of resimulation to estimate derivatives. The methods are illustrated for a path independent model (European options), a path dependent model (Asian options), and a model with multiple state variables (options with stochastic volatility).
Equivalence of Taxes and Subsidies in the Control of Production Externalities
Authors: Nault Barrie R.
Published: November 2008

We are always better off having many policies that can achieve a given objective because it extends the criteria that can be included in policy selection. This paper studies the equivalence between taxes and subsidies in the control of negative production externalities. In our models, under the tax regime, firms that take no treatment action to mitigate the damage caused by their negative externalities are punished, whereas under the subsidy regime, firms are rewarded for externality treatment activities. We employ a formulation where firms differ in the vintage of their production technology and as a result differ in profitability, negative externality generation, and the cost of treatment. We consider three measures as policy objectives: total output, total damage from negative externalities, and social welfare. We find reasonable conditions where, with an appropriate setting of uniform lump-sum and unit subsidies, the policy maker can achieve a pair of policy objectives equivalent to those obtained using unit taxes. Thus, either tax or subsidy regimes can be used to achieve desired levels of one or two policy objectives, allowing other factors such as fairness, equity, or international trade issues to be considered in policy selection.
A Graphical Analysis of Ratio-Scaled Paired Comparison Data
Authors: Genest Christian , Zhang Shuang-Shuang
Published: November 2008

One of the building blocks of the Analytic Hierarchy Process (Saaty [Saaty, T. L. 1977. A scaling method for priorities in hierarchical structures. Math. Psych. 15 234–281.]) is the ratio-scaled assessment of an agent's preferences between pairs of alternatives. This article shows how it is possible to visualize such data and to detect cardinal and ordinal inconsistencies in the respondent's judgments. The graphical method used to display preferences is not new in itself: it dates back at least to the work of Gower (Gower, J. C. 1977. The analysis of asymmetry and orthogonality. J.-R. Barra, F. Brodeau, G. Romier, B. Van Cutsem, eds. Recent Developments in Statistics. North-Holland, Amsterdam, 109–123.), and many variants of his technique can be found in the literature. But Gower plots provide an especially valuable diagnostic tool in the context of AHP, as discussed and abundantly illustrated herein.
The Value of Marketing Expertise
Authors: Paşa Mehmet , Shugan Steven M.
Published: November 2008

This paper has three objectives: (1) to construct a theoretical model that aids in evaluating marketing expertise, (2) to use that theoretical model to identify factors influencing the value of marketing expertise, and (3) to empirically test the model by observing how different market conditions influence whether companies emphasize marketing expertise. We accomplish these objectives as follows.

First, we use decision theory to find an expression for the expected value of marketing expertise. We do not use decision-analysis in the normative tradition. Nor do we assume that firms actually use formal decision-analysis. Rather, we assume that firms are rational and that decision theory describes their actions. Given that assumption, we predict how firms should evaluate marketing. Here, marketing expertise helps a firm make better marketing decisions (at least on average). Hence, the value of marketing expertise increases as marketing decisions become more important.

Second, consistent with decision theory, we predict that marketing decisions become more important with increases in the instability of the marketing environment (i.e., predictability), the profit impact of marketing decisions (i.e., opportunity profit), and the loss from marketing mistakes (i.e., potential loss).

Third, we construct empirical measures of our theoretical constructs with data from 592 firms. Our empirical results are consistent with our predictions and reveal factors influencing the value of marketing expertise. For example, greater market instability and market presence increase the value of marketing expertise, while larger organization size, organization instability, and competition decrease its value.
The Design of Optimal Conservation Programs by Electric Utilities Considering Strategic Consumer Behavior
Authors: Wirl Franz
Published: November 2008

The practice of utility demand side conservation programs, one of the most topical issues of utility management, provokes strategic reactions of consumers. As a solution of this moral hazard, optimal conservation programs are characterized when the consumers differ either with respect to their subjective time preference or with respect to the level of demand. In particular, we derive incentive compatible conservation schemes that mitigate strategic behavior. These incentives differ starkly from actual programs. First, the costs of conservation may exceed the avoided costs, yet accepting such high costs (at the margin) need not imply a large conservation. Second, such incentive scheme should bypass the inefficient consumers (e.g., the “poor”) but should instead target consumers who act efficiently and have a high demand (e.g., the “rich”).
When Should a Roving Server Be Patient?
Authors: Srinivasan Mandyam M. , Gupta Diwakar
Published: November 2008

When polling systems are used to model real-world systems, it is typically assumed that the server switches continuously (“roves”) even when there are no waiting jobs in the system. However, requiring the server to be patient, instead of having it rove, might be more realistic. Furthermore, operational control of these systems can be improved by knowing answers to questions like “under what circumstances should be roving server be patient?” and “at which stations?”.

This paper analyzes the patient server model and provides explicit expressions for the waiting time distributions, the mean waiting times and the pseudo-conservation law. Several variants of the patient server model are considered. We show that while the patient server mechanism is generally better than the roving server mechanism in the work-in-process (WIP) reduction sense, there do exist cases where roving is better. Counter-intuitive examples where reducing switchover time can increase WIP are also reported.
A Note on Variance Reducing Group Maintenance Policies
Authors: Wilson John G.
Published: November 2008

Group replacement policies for machines operating in parallel are generally evaluated by computing the associated expected cost per unit time. However, as with all stochastically evolving systems, variance should play an important managerial role. No matter which policy is used by the maintenance manager, knowledge of the associated variance provides important information about the variability of the costs that will be incurred by using this policy. Additionally, there will be cases where a decision maker is willing to incur increased expected cost per unit time in order to reduce the variability of the costs among cycles. This paper demonstrates that it is feasible and practicable to calculate the variance of the cost per unit time associated with group maintenance policies.
Procedural Justice and Managers' In-Role and Extra-Role Behavior: The Case of the Multinational
Authors: Kim W. Chan , Mauborgne Renée A.
Published: November 2008

Existing procedural justice studies to date offer only pieces of the picture on how procedural justice judgments affect behavior. Besides, these studies have been conducted primarily in the legal context. This paper develops a comprehensive picture of how procedural justice affects managers' in-role and extra-role behavior in the business context. It does so by examining the direct and indirect effects of procedural justice judgments on the in-role and extra-role behavior of multinationals' subsidiary top management in the context of the global resource allocation decision process. Especially, this paper advances and tests a theory which predicts that the attitude of commitment to support decisions provides a bridge between procedural justice and extra-role behavior. Based on an analysis of 119 subsidiary top managers, we offer evidence in support of this theory. Besides its contribution to the procedural justice literature, our study also sheds light on one of the most pressing issues outstanding in the field of international management: how multinationals can motivate subsidiary top managers to implement their global resource allocation decisions. The results suggest that the exercise of procedural justice inspires managers to go beyond the call of duty and engage in innovative actions, spontaneous cooperation, and creative behavior on behalf of the organization in their execution of decisions.
Paradox Lost? Firm-Level Evidence on the Returns to Information Systems Spending
Authors: Brynjolfsson Erik , Hitt Lorin
Published: November 2008

The “productivity paradox” of information systems (IS) is that, despite enormous improvements in the underlying technology, the benefits of IS spending have not been found in aggregate output statistics. One explanation is that IS spending may lead to increases in product quality or variety which tend to be overlooked in the aggregate statistics, even if they increase output at the firm-level. Furthermore, the restructuring and cost-cutting that are often necessary to realize the potential benefits of IS have only recently been undertaken in many firms.

Our study uses new firm-level data on several components of IS spending for 1987–1991. The dataset includes 367 large firms which generated approximately 1.8 trillion dollars in output in 1991. We supplemented the IS data with data on other inputs, output, and price deflators from other sources. As a result, we could assess several econometric models of the contribution of IS to firm-level productivity.

Our results indicate that IS spending has made a substantial and statistically significant contribution to firm output. We find that the gross marginal product (MP) for computer capital averaged 81% for the firms in our sample. We find that the MP for computer capital is at least as large as the marginal product of other types of capital investment and that, dollar for dollar, IS labor spending generates at least as much output as spending on non-IS labor and expenses. Because the models we applied were similar to those that have been previously used to assess the contribution of IS and other factors of production, we attribute the different results to the fact that our data set is more current and larger than others explored. We conclude that the productivity paradox disappeared by 1991, at least in our sample of firms.
Optimal Shift Scheduling with Multiple Break Windows
Authors: Aykin Turgut
Published: November 2008

This paper presents a new integer programming model for optimal shift scheduling with multiple rest and lunch breaks, and break windows. A set-covering approach for this problem was originally developed by Dantzig (1954). Since then, a number of set-covering-based formulations have been proposed in the literature. These formulations require an integer variable for every shift type, shift start time, and rest/lunch break placement combination. Unfortunately, the number of integer variables required is rather large, making them impractical to solve for an optimal solution in most applications. We present a new approach in which a set of break variables is introduced for every shift-break type combination to determine the break placements. This approach leads to a significantly improved integer programming model requiring substantially smaller number of variables and computer memory. We tested the proposed approach with 40 test problems involving between 1,728 and 8,640 shift variations, and five demand patterns. Our results showed that the proposed formulation is very useful in solving large shift scheduling problems optimally.
Task Complexity, Equilibrium Selection, and Learning: An Experimental Study
Authors: Ho Teck-Hua , Weigelt Keith
Published: November 2008

We consider several coordination games with multiple equilibria each of which is a different division of a fixed pie. Laboratory experiments are conducted to address whether “task complexity” affects the selection of equilibrium by subjects. Three measures of task complexity—cardinality of choice space, level of iterative knowledge of rationality, and level of iterative knowledge of strategy—are manipulated and tested. Results suggest the three measures can predict choice behavior. Since strategically equivalent games can have different task complexity measures, our results imply that subjects are sensitive to game form presentation. We also fit data using three adaptive learning models: 1) Cournot, 2) Fictitious Play, and 3) Payoff Reinforcement, in increasing order of required cognitive effort. The Fictitious Play model, which tracks only cumulative frequencies of opponents' past behaviors fits the data best.
Optimization of the Transient and Steady-State Behavior of Discrete Event Systems
Authors: Andradóttir Sigrún
Published: November 2008

We present a general framework for applying simulation to optimize the behavior of discrete event systems. Our approach involves modeling the discrete event system under study as a general state space Markov chain whose distribution depends on the decision parameters. We then show how simulation and the likelihood ratio method can be used to evaluate the performance measure of interest and its gradient, and we present conditions that guarantee that the Robbins-Monro stochastic approximation algorithm will converge almost surely to the optimal values of the decision parameters. Both transient and steady-state performance measures are considered. For steady-state performance measures, we consider both the case when the Markov chain of interest is regenerative in the standard sense, as well as the case when this Markov chain is Harris recurrent, and thereby regenerative in a wider sense.
A Lagrangean-Based Heuristic for Dynamic Multilevel Multiitem Constrained Lotsizing with Setup Times
Authors: Tempelmeier Horst , Derstroff Matthias
Published: November 2008

In this paper a heuristic approach for the dynamic multilevel multiitem lotsizing problem in general product structures with multiple constrained resources and setup times is proposed. With the help of Lagrangean relaxation the capacitated multilevel multiitem lotsizing problem is decomposed into several uncapacitated single-item lotsizing problems. From the solutions of these single-item problems lower bounds on the minimum objective function value are derived. Upper bounds are generated by means of a heuristic finite scheduling procedure. The quality of the approach is tested with reference to various problem groups of differing sizes.
Using the Deterministic EOQ Formula in Stochastic Inventory Control
Authors: Axsäter Sven
Published: November 2008

This note gives an improved bound (√5 − 2)/2 ≈ 0.1180 for the relative cost increase when using the deterministic EOQ formula as a heuristic solution when demands are stochastic. We also discuss under what circumstances this bound is tight.
Solving Multiple Objective Programming Problems Using Feed-Forward Artificial Neural Networks: The Interactive FFANN Procedure
Authors: Sun Minghe , Stam Antonie , Steuer Ralph E.
Published: November 2008

In this paper, we propose a new interactive procedure for solving multiple objective programming problems. Based upon feed-forward artificial neural networks (FFANNs), the method is called the Interactive FFANN Procedure. In the procedure, the decision maker articulates preference information over representative samples from the nondominated set either by assigning preference “values” to the sample solutions or by making pairwise comparisons in a fashion similar to that in the Analytic Hierarchy Process. With this information, a FFANN is trained to represent the decision maker's preference structure. Then, using the FFANN, an optimization problem is solved to search for improved solutions. An example is given to illustrate the Interactive FFANN Procedure. Also, the procedure is compared computationally with the Tchebycheff Method (Steuer and Choo [Steuer, R. E., E.-U. Choo. 1983. An interactive weighted Tchebycheff procedure for multiple objective programming. Math. Programming 26(1) 326–344.]). The computational results indicate that the Interactive FFANN Procedure produces good solutions and is robust with regard to the neural network architecture.
The Effect of Uncertainty and Information Asymmetry on the Structure of Compensation Contracts: A Test of Competing Models
Authors: Umanath Narayan S. , Ray Manash R. , Campbell Terry L.
Published: November 2008

This research note reports results of a laboratory experiment conducted as a follow-up investigation of an earlier study by Umanath, Ray and Campbell (Umanath, N. S., M. R. Ray, T. L. Campbell. 1993. The impact of perceived environmental uncertainty and perceived agent effectiveness on the composition of compensation contracts. Management Sci. (January) 32–45.). Here, we focus on a specific unexpected result of Umanath et al. who found evidence contradicting the theoretical prediction with respect to the impact of environmental uncertainty on the composition of compensation contracts. Umanath et al., in retrospect, offered an explanation for their unexpected finding based on an alternative theory under the same agency framework. Our results not only ratify the alternative explanation offered by Umanath et al., but also identify information symmetry/asymmetry as the contingent factor capable of reconciling the apparently contradicting predictions of the two agency-based theories used in this research.
The Magnitude of Errors in Proximal Multiattribute Decision Analysis with Probabilistically Dependent Attributes
Authors: Corner James L. , Kirkwood Craig W.
Published: November 2008

This paper investigates the accuracy of an approximation procedure for evaluating alternatives under uncertainty with multiple evaluation attributes. This approximation uses only the first two moments of the probability distributions for the alternatives, and hence it can substantially reduce the amount of information which must be collected in order to evaluate alternatives when evaluation attributes are probabilistically dependent. The accuracy of the approximation is investigated by comparing results from using it with exact calculations for a variety of situations representative of those found in decision analysis practice. This investigation shows that the approximation is accurate for situations representative of many decision analysis applications. However, caution is needed in applying the approximation in some situations where it may give inaccurate results. Characteristics of cases where the approximation is less accurate are presented.
Impact of Plant Size and Focus on Productivity: An Empirical Study
Authors: Brush Thomas , Karnani Aneel
Published: November 2008

Recent popular business literature has suggested that there is a significant trend in the United States for firms to decrease the size and increase the focus of manufacturing plants they operate, and that this leads to higher productivity. This paper tests empirically the validity of these claims. We analyze data on virtually the entire population of manufacturing plants in the United States and find that, contrary to the popular business literature, the average size of plants increased during the period 1972–1984. However, consistent with the popular notion, the rate of growth in plant size slowed considerably, and even turned negative for a category of large plants. Plant focus did increase during this period. We then investigate the relationship between productivity and plant characteristics including plant size and plant focus. Overall, our results do not support the popular argument that reduction in plant size results in productivity gains. However, we do find support for this argument in some two-digit SIC industries; also, scale economies in the entire population decreased over the period 1972–1982. We also find only limited support for the popular argument that plant focus increases productivity.
Self-Buffering, Self-Balancing, Self-Flushing Production Lines
Authors: Zavadlav Emil , McClain John O. , Thomas L. Joseph
Published: November 2008

This research addresses a system of flexible worker assignments in a setting where there are more workers than machines. When organized using this system, a production line balances itself by shifting the workloads continuously and automatically in response to changes in the state of the system. The system is, in effect, buffering itself against variation by altering the work assignments on the fly. This allows the system to operate with very low levels of work-in-process inventory (WIP).

In this paper, the workers (rather than machines) are the factor that limits the rate of output. We also assume that the line has a “U” shape, but many of the results do not depend on this topology. An industrial example is described.

The system has some interesting and counter-intuitive properties which we demonstrate under a variety of circumstances through an exploratory approach that uses both Markovian and simulation models. Several different policies are compared under conditions of processing time uncertainty. We demonstrate that a flexible assignment system can outperform fixed assignments in a variety of circumstances. Of particular interest is the near absence of balance delay, even when the tasks cannot be divided equally among the workers.
A Multidimensional Model of Client Success When Engaging External Consultants
Authors: Gable Guy G.
Published: November 2008

Too often the relationship between clients and external consultants is perceived as one of protagonist versus antagonist. Stories on dramatic, failed consultancies abound, as do related anecdotal quips. A contributing factor to many “apparently” failed consultancies is a poor appreciation by both the client and consultant of the client's true goals for the project and how to assess progress toward these goals. This paper presents and analyses a measurement model for assessing client success when engaging an external consultant. Three main areas of assessment are identified: (1) the consultant's recommendations, (2) client learning, and (3) consultant performance. Engagement success is empirically measured along these dimensions through a series of case studies and a subsequent survey of clients and consultants involved in 85 computer-based information system selection projects. Validation of the model constructs suggests the existence of six distinct and individually important dimensions of engagement success. Both clients and consultants are encouraged to attend to these dimensions in pre-engagement proposal and selection processes, and post-engagement evaluation of outcomes.
National and Corporate Cultural Fit in Mergers/Acquisitions: An Exploratory Study
Authors: Weber Yaakov , Shenkar Oded , Raveh Adi
Published: November 2008

While cultural fit has been acknowledged to be a potentially important factor in mergers and acquisitions, the concept has been ill-defined, with no distinction drawn between the national and corporate levels of culture. By examining both international and domestic mergers, the present study assesses the relative role of national and corporate cultural fit in predicting effective integration between merger partners. The innovative, nonparametric co-plot method is introduced, and its main advantage—the simultaneous consideration of both variables and observations—is utilized to explore cultural fit in the two groups of mergers. The findings confirm that national and corporate culture are separate constructs with variable attitudinal and behavioral correlates.
Overlapping Start-Time Bands in Implicit Tour Scheduling
Authors: Jacobs Larry W. , Brusco Michael J.
Published: November 2008

Many organizations face personnel scheduling decisions under conditions of variable demand for service across a seven-day planning horizon. These organizations must assign employees to daily shifts that efficiently satisfy the demand for labor, yet allow adequate time for rest between subsequent shifts of an employee's weekly tour schedule. To meet these diverse objectives, managers may permit shifts to begin (and end) in any planning period of the day, but place bands on shift-start times to which individuals may be assigned on each day of their tour schedule.

We present a compact integer programming model that implicitly represents start-time band scheduling flexibility. We demonstrate the new model by applying it to requirements for toll collectors on the Illinois Tollway. Problems requiring up to two million variables using a general set covering formulation were represented using the new implicit programming model and often solved to optimality in just a few minutes on a Pentium-based microcomputer. The results indicate that start-time bands can provide an important improvement in scheduling efficiency when compared to the exclusive use of schedules that require workers to begin work on the same hour of the day on each day of their tour.
Rare-Event Simulation for Multistage Production-Inventory Systems
Authors: Glasserman Paul , Liu Tai-Wen
Published: November 2008

We consider the problem of precise estimation of service-level measures in multistage production-inventory systems when the system is managed for high levels of service. Precisely because the service level is high, stockouts, large backorders, and unfilled demands are rare and thus difficult to estimate by straightforward simulation. We propose and analyze alternative estimators, based on changing the demand distribution to make these rare events less rare. Whereas straightforward simulation for a fixed relative error results in computational requirements that grow exponentially in certain stock-level parameters, the requirements for our importance sampling estimators remain bounded for all parameter values. We provide bounds making it possible to determine the maximum number of replications required before any are generated. Numerical examples illustrate the effectiveness of our method.
Fairness and Social Risk II: Aggregated Analyses
Authors: Fishburn Peter C. , Sarin Rakesh K.
Published: November 2008

This paper is the second of a two-paper study of fairness issues for decisions that affect the benefits received and the risks encountered by a population. The study examines fairness for individuals and for homogeneous groups within the population. It considers fairness both for population benefit-risk profiles and for probability distributions over profiles.

Our study bases fairness on notions of envy among individuals and groups. The first paper focused on fairness in profiles and profile distributions when benefits and risks are not aggregated. The present paper uses individual preferences to assess fairness when benefits and risks are aggregated within groups or over the population. It concentrates on intergroup envy measures and fairness indices that account for ways that aggregated benefits and risks might be allocated to members of groups or to groups within the population.
Modelling the Costs and Benefits of Delayed Product Differentiation
Authors: Lee Hau L. , Tang Christopher S.
Published: November 2008

Expanding product variety and high customer service provision are both major challenges for manufacturers to compete in the global market. In addition to many ongoing programs, such as lead-time reduction, redesigning products and processes so as to delay the point of product differentiation is becoming an emerging means to address these challenges. Such a strategy calls for redesigning products and processes so that the stages of the production process in which a common process is used are prolonged. This product/process redesign will defer the point of differentiation (i.e., defer the stage after which the products assume their unique identities). In this paper, we develop a simple model that captures the costs and benefits associated with this redesign strategy. We apply this simple model to analyze some special cases that are motivated by real examples. These special cases enable us to formalize three different product/process redesign approaches (standardization, modular design, and process restructuring) for delaying product differentiation that some companies are beginning to pursue. Finally, we analyze some special theoretical cases that enable us to characterize the optimal point of product differentiation and derive managerial insights.
Periodic Pricing of Seasonal Products in Retailing
Authors: Bitran Gabriel R. , Mondschein Susana V.
Published: November 2008

This paper studies intertemporal pricing policies when selling seasonal products in retail stores. We first present a continuous time model where a seller faces a stochastic arrival of customers with different valuations of the product. For this model, we characterize the optimal pricing policies as functions of time and inventory. We use this model as a benchmark against which we compare more realistic models that consider periodic pricing reviews. We show that the structure of the optimal pricing policies in this case is consistent with the procedures observed in practice; retail stores successively discount the product during the season and promote a liquidation sale at the end of the planning horizon. We also show that the loss experienced when implementing periodic pricing reviews instead of continuous policies is small when the appropriate number of reviews is chosen. Several interesting economic insights emerge from our analysis. For example, uncertainty in the demand for new products leads to higher prices, larger discounts, and more unsold inventory. Finally, we study the effect of announced discount policies on prices and profits. We show that stores that have adopted this type of strategy usually set prices such that with high probability the merchandise is sold during the first periods and the largest discounts rarely take place.
The Assimilation of Software Process Innovations: An Organizational Learning Perspective
Authors: Fichman Robert G. , Kemerer Chris F.
Published: November 2008

The burden of organizational learning surrounding software process innovations (SPIs)—and complex organizational technologies in general—creates a “knowledge barrier” that inhibits diffusion. Attewell (Attewell, P. 1992. Technology diffusion and organizational learning the case of business computing. Organ. Sci. 3(1) 1–19.) has suggested that many organizations will defer adoption until knowledge barriers have been sufficiently lowered; however, this leaves open the question of which organizations should be more likely to innovate, even in face of high knowledge barriers. It is proposed here that organizations will innovate in the presence of knowledge barriers when the burden of organizational learning is effectively lower, either because much of the required know-how already exists within the organization, or because such knowledge can be acquired more easily or more economically. Specifically, it is hypothesized that organizations will have a greater propensity to initiate and sustain the assimilation of SPIs when they have a greater scale of activities over which learning costs can be spread (learning-related scale), more extensive existing knowledge related to the focal innovation (related knowledge), and a greater diversity of technical knowledge and activities (diversity). An empirical study using data on the assimilation of object-oriented programming languages (OOPLs) by 608 information technology organizations strongly confirmed the importance of the three hypothesized factors in explaining the assimilation of OOPLs.