A NOTE ON RENEGING DECISIONS

This note is an extension of the approach to the problem of reneging introduced in Parkan and Warren [1]. It is assumed customers consider joining an M/M/1 queuing system with a prior gamma distribution over the values of the mean service time. Thus, each customer has an initial estimate of his total waiting time in the system. The customers associate the same sunk value with the waiting time and obtain the same reward at service completion. Having joined a system each customer may consider reneging in view of his revision of his initial service time estimate based on service observations. The bounds on the stationary state probabilities for such a system are obtained and examples are provided to compare the cases with and without reneging.     

A NOTE ON LEARNING CURVE PARAMETERS

This note describes differences in the feasible range of values that the learning curve parameter may take when a unit learning approach is used as opposed to a cumulative-average learning curve. Clarification of this point is important because learning curve theory now is used in a variety of areas.     

A NOTE ON HOLDING COSTS AND LOT-SIZE ERRORS

This note examines the sensitivity of the basic economic-order-quantity inventory model to lot-size errors when holding costs are assumed to be a strictly increasing (though not necessarily linear) function of average inventory. In particular, we show that the penalty associated with ordering either too much or too little is a function not only of the size of the error but of the shape of the holding-cost curve as well. We demonstrate that, under certain conditions, even relatively small lot-size errors can be extremely costly.     

A NOTE ON DYNAMIC LOT SIZING IN A ROLLING-HORIZON ENVIRONMENT

This paper presents a modification of the dynamic lot-size algorithm of Wagner and Whitin for rolling horizon environments. The computational results show that the modified algorithm gives better cost performance than the Wagner-Whitin algorithm and the Silver-Meal heuristic. The improvements over the Wagner-Whitin algorithm require very few additional computations.     

A NOTE ON A MULTIVARIATE GENERALIZATION OF THE KRUSKAL-WALLIS TEST

Marketers are often interested in testing whether the mean vectors of multivariate distributions are equal. The test usually applied, one-way MANOVA, assumes the distributions are multinormal. Unfortunately, this assumption is not supported in many studies. As an alternative, a nonparametric multivariate one-way analysis of variance procedure is presented.     

A NOTE ON INTEGRATING INVENTORY AND PRODUCT SALES-MIX MODELS

In a recent issue of Decision Sciences, Raiborn and Harris [2] discussed the integration of inventory and product sales-mix models. While they formulated a model which reflected some of the interactions between product sales-mix and inventory decisions, the purpose of this note is to point out deficiencies in their decision rule analysis for solving such integrated models.     

A NOTE ON AN APPLICATION OF THE ANALYTIC HIERARCHY PROCESS

This note is a response to an article by Zahedi [2] published in the Winter 1985 issue of Decision Sciences. It demonstrates that there is no need to calculate eigenvalues for consistent pairwise comparison matrices in order to calculate normalized values of attributes.     

A NOTE ON USER SOLUTION STRATEGY FOR MIXED-INTEGER LINEAR PROGRAMMING MODELS

Large-scale mixed-integer linear programming (MILP) models may easily prove extraordinarily difficult to solve, even with efficient commercially implemented MILP solution codes. Drawing on experience gained in solving and analyzing three intertemporal investment planning MILP models for electric power supply, this note offers several practical suggestions for reducing computer solution times for general production-allocation MILP models. Solution time reduction stems from judicious use of the powerful computational capabilities of existing commercial linear programming codes in conjunction with information known or to be learned by the practitioner about the model's structure.     

A TEACHING NOTE ON THE USE OF ASSUMPTIONS IN CASE STUDY

This note describes a modification in the conventional case method of instruction. The modification, which deals with the problem caused by each student making a different set of assumptions for a given case, has successfully met the test of classroom use.