摘要:

This paper demonstrates that the problem of optimizing the work output of an individual employee, subject to a set of fixed‐duration rest periods over a continuous time horizon, can be modeled with a quadratic programming formulation. Exogenous determination of break period durations may result from union contracts, management policies, or necessary lower bounds on break time due to transportation or other requirements. Although the new formulation is more complex than that required for previous models, an efficient solution procedure is presented which avoids the complexities of nonlinear programming. The number of iterations required for convergence is bounded from above by the number of rest periods to be scheduled and all computations are simple. An illustration of the procedure demonstrates that it may be effectively used without computer support. While this research was motivated by the fact that previous work‐rest models were not applicable to work horizons which contained a fixed‐duration meal break, the procedure can be used to obtain optimal placement for a set of fixed‐duration rest periods which may or may not include a meal break. The characteristics of optimal strategies for a set of fixed‐duration breaks proofs are shown to have implications for the design of shifts which are potentially more attractive and productive than shifts based upon typical practice. These characteristics are also compared to the general characteristics of optimal policies associated with endogenously determined break durations. This comparison provides insight into the possible consequences of exogenous determination of break durations. This paper concludes with suggestions for additional

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1991.tb01268.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

This article illustrates the substantial effects employee movements (i.e., movements due to employee promotions, transfers, and separations) have on the value of a human resource intervention. Two methods for estimating differential employee movements are presented and their resulting utility estimates are contrasted and compared. Finally, the advantages and disadvantages of each procedure are discussed as well as the value such information provides to organizational decision makers.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1991.tb01269.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

This paper attempts to modify financial portfolio theory for application in product portfolio decisions. The proposed multiperiod portfolio framework should help marketers in allocating scarce corporate resources to various competing products as well as contribute to developing a body of theory to solve an important problem in marketing management. Managerial and theoretical implications are discussed.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1991.tb01270.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The creation of new food sources is an important advancement in the search for solutions to food shortages in both developing and underdeveloped countries. Aquaculture, the production of aquatic animals under controlled conditions, offers exciting new possibilities for alternative protein sources in a wide variety of locales. This paper presents a mathematical programming model designed to aid the manager of an aquaculture facility in production scheduling and the evaluation of new technologies in this rapidly changing environment.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1991.tb01271.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

In an earlier issue ofDecision Sciences, Jesse, Mitra, and Cox [1] examined the impact of inflationary conditions on the economic order quantity (EOQ) formula. Specifically, the authors analyzed the effect of inflation on order quantity decisions by means of a model that takes into account both inflationary trends and time discounting (over an infinite time horizon). In their analysis, the authors utilized two models: Current‐dollars model and Constant‐dollars model. These models were derived, of course, by setting up a total cost equation in the usual manner then finding the optimum order quantity that minimizes the total cost. Jesse, Mitra, and Cox [1]found that EOQ is approximately the same under both conditions; with or without inflation. However, we disagree with the conclusion drawn by [2] and show that EOQ will be different under inflationary conditions, provided that the inflationary conditions are properly accounted for in the formulation of the total cost mo

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1991.tb01272.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

In a recent article, Chatterjee and Greenwood [1] addressed the problem of multicollinearity in polynomial regression models. They noted that there is a high correlation betweenXandX2; therefore, a second‐order polynomial model suffers the consequences of collinearity. Chatterjee and Greenwood [1] suggested a method they believe will overcome the problem. The contention of the present comment is that the suggested method accomplishes nothing and, indeed, has the potential to lead the unwary researcher to the wrong inference and misinterpretation of his result

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1991.tb01273.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY