RESOURCE PLANNING FOR MULTIPLE PROJECTS *

This paper is concerned with the estimation of the resource requirements to service multiple projects that use many types of resources. It reports on a systematic procedure to determine the low cost levels of these resources, focusing on the two following characteristics: (1) the comparative cost of standard time to overtime in the utilization of these resources for the economical completion of the projects, and (2) the impact of highly expensive equipment in the determination of the economic levels of the manpower resources that combine with the equipment to form a crew. A numerical example is also presented to illustrate the method. Resource planning is of particular interest in the area of multiproject scheduling, since most of the commonly utilized heuristic solution approaches focus on the allocation of a limited set of available resources. In the corporate strategic planning functions, resource planning is particularly important for capital investment, training and development, and procurement scheduling.     

MANAGING PRODUCT VARIETY: AN INTEGRATIVE REVIEW AND RESEARCH DIRECTIONS

Variety management has emerged as a crucial dimension of successful business practice. In this paper, I first provide a framework for managerial decisions about variety. Variety‐creation decisions determine the amount, type, and timing of end‐product variety, while variety‐implementation decisions focus on the design and operation of internal processes and a supply chain to support a firm's variety‐creation strategy. I organize variety‐related decisions into four key decision themes in variety creation: 1) dimensions of variety, 2) product architecture, 3) degree of customization, and 4) timing; and three key decision themes in variety implementation: 1) process capabilities, 2) points of variegation, and 3) day‐to‐day decisions. I describe each theme and review the relevant literature on each theme, with a focus on research that provides insight to problems faced in practice. Finally, I identify untapped avenues for future research that would be of value to the practicing manager, paying special attention to interdependencies among decision themes.     

THE ACADEMIC FLOW MODEL: A MARKOV-CHAIN MODEL FOR FACULTY PLANNING*

A Markov-chain faculty planning model to be used with institution-specific data is presented to describe and better understand the complex phenomena of faculty movement through an institution and on its relationship to salary costs, composition of the faculty, and faculty turnover rate. The model updates the earlier work done at Stanford University and Oregon State University by the addition of states for fixed-term appointments and for part-time FTEs to reflect accurately the current hiring trends at many institutions. The model is implemented and tested at two different institutions. The findings suggest that the model is a viable means of gaining useful insights and quantitative data on the faculty profile, salary costs, expected departures, and part-time trends. And further, when used as a planning tool, and the model apparently is comprehensive and flexible enough to analyze the probable effects, both in the short and long run, of alternative personnel policies on the faculty composition.     

THE EFFECTS OF INTERDISCIPLINARY EDUCATIONAL FORMATS ON CONCEPT RETENTION AND PROBLEM–SOLVING ABILITY*

The purpose of this study was to examine the effects of different interdisciplinary problem-oriented formats on a student's knowledge of and retention of disciplinary concepts and principles, his application of these concepts and principles to disciplinary problems, and his use of a discipline in his analysis of a complex problem. Performances of students enrolled in the experimental sections were compared to those of students enrolled in standard lecture-discussion sections. Regression analysis was used to analyze students' performance in order to control the effects of differences in student backgrounds. It was found that altering the pedagogical format and reward system within the experimental sections had no significant effect upon student performances in the experimental, problem-oriented program. In general, this study indicates that students taught in the standard lecture-discussion format in which grades are determined by examination over course material retain concepts and principles, apply these concepts and principles to disciplinary problems, and integrate disciplinary concepts into their analysis of complex problems as well as, if not better than, students taught in an interdisciplinary, problem-solving format.     

MANAGING CREDIT BUBBLES

We study a dynamic economy where credit is limited by insufficient collateral and, as a result, investment and output are too low. In this environment, changes in investor sentiment or market expectations can give rise to credit bubbles, that is, expansions in credit that are backed not by expectations of future profits (i.e., fundamental collateral), but instead by expectations of future credit (i.e., bubbly collateral). Credit bubbles raise the availability of credit for entrepreneurs: this is the crowding‐in effect. However, entrepreneurs must also use some of this credit to cancel past credit: this is the crowding‐out effect. There is an “optimal” bubble size that trades off these two effects and maximizes long‐run output and consumption. The equilibrium bubble size depends on investor sentiment, however, and it typically does not coincide with the “optimal” bubble size. This provides a new rationale for macroprudential policy. A credit management agency (CMA) can replicate the “optimal” bubble by taxing credit when the equilibrium bubble is too high and subsidizing credit when the equilibrium bubble is too low. This leaning‐against‐the‐wind policy maximizes output and consumption. Moreover, the same conditions that make this policy desirable guarantee that a CMA has the resources to implement it.     

MANAGING CYCLIC INVENTORIES

Cyclic inventory is the buffer following a machine that cycles over a set of products, each of which is subsequently consumed in a continuous manner. Scheduling such a machine is interesting when the changeover times from one product to another are non‐trivial—which is generally the case. This problem has a substantial literature, but the common practices of “lot‐splitting” and “maximization of utilization” suggest that many practitioners still do not fully understand the principles of cyclic inventory. This paper is a tutorial that demonstrates those principles. We show that cyclic inventory is directly proportional to cycle length, which in turn is directly proportional to total changeover time, and inversely proportional to machine utilization. We demonstrate the virtue of “maximum changeover policies” in minimizing cyclic inventory—and the difficulty in making the transition to an increased level of demand. In so doing, we explicate the different roles of cyclic inventory, transitional inventory, and safety stock. We demonstrate the interdependence of the products in the cycle—the lot‐size for one product cannot be set independently of the remaining products. We also give necessary conditions for consideration of improper schedules (i.e., where a product can appear more than once in the cycle), and demonstrate that both lot‐splitting and maximization of utilization are devastatingly counter‐productive when changeover time is non‐trivial.     

POTENTIAL RESEARCH TOPICS IN DECISION ANALYSIS*

Robert L. Winkler's paper [1] provides a comprehensive overview of challenging research areas for decision making under uncertainty. Hence, rather than try to extend the list of research areas identified, this note will attempt to embellish some that I feel are particularly important. In these areas, I feel the value of systematic research is particularly high. For convenience, the discussion will be organized under the four research categories identified by Winkler with a couple of sugestions following in an “implementation research” category. The reader will note, however, that many of the suggested topics actually relate to more than one research category.     

TRACKING PRODUCT-PROCESS INTERACTIONS: A RESEARCH PARADIGM*

To design (or redesign) a competitive product, it is imperative that both the sales and manufacturing cost implications are assessed in a structured way. That is, the interactive (multidimensional) aspects of manufacturing and marketing variables need to be positioned in a proper perspective so that the system impact of variation in one or more variables may be ascertained quickly. In this paper we show how some of the system-related paradigms can be used as foundations for developing quantitative and qualitative models for tracking such interactive ímpacts. The emphasis is not on building complex mathematical models to solve specific problems but on providing a framework where system properties expressed as simple postulates can be used in an intelligent way to assess the impact of improvements in specific product-process scenarios.     

Education DEVELOPMENT AND VALIDATION OF A TOOL FOR ASSIGNING STUDENTS TO GROUPS FOR CLASS PROJECTS*

Group project work is an integral part of many university courses. Assigning students to project groups can be difficult because of the students' diverse backgrounds. Many instructors therefore decide not to assign group projects. This paper develops and validates an instrument that assigns both experienced and inexperienced students to different project groups, thereby creating a balanced, fair environment. The instrument is checked for reliability and validity and then is used to assign students to different project groups. Based on group performance, the end-of-the-semester results also are provided. Path analysis is used to test a causal model. Conclusions and implications for future research are presented.     

MANAGING PRODUCT RETURNS FOR REMANUFACTURING

Firms are often encouraged to offer environmentally friendly products as a demonstration of corporate citizenship. However, this may prove to be an unrealistic expectation since a rational firm will only engage in profitable ventures; those that increase shareholder wealth. We develop a framework for analyzing the profitability of reuse activities and show how the management of product returns influences operational requirements. We show that the acquisition of used products may be used as the control lever for the management and profitability of reuse activities. These activities, termed product acquisition management, affect several important business decisions. First, if a firm is to pursue reuse activities, these reuse activities must be value‐creating. Second, if a firm is to compete by offering remanufactured products, then we show how product returns management influences the overall profitability of such activities via a trial and error EVA approach. Third, we show how operational issues are strongly affected by the approach used to manage product returns. There is a need for future research specifying the mathematical relationship between acquisition price and the nominal quality of the returned product.     

PORTFOLIOS OF RISKY PROJECTS

The problem of selecting a portfolio from a set of independent risky business ventures is formulated in terms of maximization of the risk-adjusted (certainty-equivalent) profit of the portfolio, based upon the exponential utility function. Objects of investment include fractional participation (risk sharing) in projects with other firms, where costs and returns are shared in the same proportion. The method assumes that project costs are certain. Project revenues are uncertain, and any probability function for revenue can be used.     

PRACTICE‐FOCUSED RESEARCH ISSUES FOR SCHEDULING SYSTEMS*

Scheduling research has had relatively little impact on manufacturing practice, yet within the last several years, there has been an explosive growth in the development and implementation of computer‐based scheduling systems in industry. Changes in the environment have increased the stakes and the opportunities for the results of scheduling research to influence manufacturing competitiveness. This paper draws on field‐related experiences with the development and implementation of scheduling systems to propose high‐impact research topics.     

COMPUTER GRAPHICS AS DECISION AIDS: DIRECTIONS FOR RESEARCH*

Computer-generated graphics are becoming increasingly available to decision makers. Despite claims on the part of vendors that the use of graphics will improve decision speed and quality over traditional methods of data display, the available evidence is far from supportive. Initial studies show graphics to be no more effective in communicating information than tables. Correct interpretation of graphical displays appears to require training, which most users lack. Furthermore, there is evidence that those features that make a graph visually attractive—such as color, design complexity, and realism—may actually detract from accurate comprehension. This paper summarizes the literature dealing with the human use of graphics, develops several propositions based on persistent trends in the literature, and suggests directions for future research.     

THE PREDICTIVE ABILITY CRITERION IN EXPERIMENTAL JUDGMENT RESEARCH IN ACCOUNTING*

Previous experimental judgment research in accounting has been interpreted as supportive of the linear model as an appropriate representation of decision-making behavior in nearly all of the tasks investigated. Moreover, nonlinear models have come to be viewed as adding relatively little predictive power over that provided by the linear model, even in tasks considered to be inherently nonlinear. These conclusions were based largely upon evaluating the predictive ability of the linear model in terms of statistics measuring the proportion of variance accounted for by the model. In the present paper it is argued that, since these statistics are not independent of the experimental design, it is not clear whether the high correlations are indicative of the model's success in representing decision-making processes or instead are more the result of various features of the experimental design. It is suggested that correlational tests be supplemented with qualitative tests of the predictive ability of a model. Implications for accounting are discussed.     

INDUSTRY RESOURCE ALLOCATION TO BASIC RESEARCH UNDER NORMALLY DISTRIBUTED BENEFITS*

The failure of a free market system to attain socially optimal allocation of resources to research and development (R&D) is a generally recognized problem. However, we are just beginning to understand the types of R&D activities that receive relatively serious underinvestment from specific types of industries and the types of governmental intervention strategies that are likely to be effective and efficient in the correction of that underinvestment. Recently, Joglekar and Hamburg [16] [17] sought answers to these types of questions using models of the resource allocation behavior of firms considering investment in basic research related to their industry. It was assumed that the firms' benefits were exponentially distributed. In the present article, such benefits are assumed to be normally distributed, and an attempt is made to verify the earlier conclusions and policy implications of [16] and [17]. The results are similar for these two substantially different types of distribution, but the earlier conclusions and policy implications are clarified, qualified, and extended.     

THE USES OF BUSINESS GAMING IN EDUCATION AND LABORATORY RESEARCH*

This paper reports an empirical investigation of business gaming in education and research. Subjects were approximately 200 junior and senior undergraduate students who were assigned to seven-man teams on the basis of scores on the Least Preferred Co-worker (LPC) leadership style questionnaire, and who played the Marksim business game during one academic semester. Relationships were explored between post-game perceptions of the game, team atmosphere and the leader, combinations of congruent and incongruent leadership styles, and measures of team performance. Also explored were relationships between several predictor variables (including grade point average) and measures of team performance. The results were generally disappointing in regard to business gaming as an educational tool. However, it seems that business gaming may hold promise for laboratory research in the behavioral sciences. The results of this investigation suggest that relationship-oriented and task-oriented leadership styles and combinations of these styles within hierarchically structured groups affect members' perceptions of the task and other aspects of the task environment but do not affect group performance, at least directly. These results may have significance for those interested in organizational design and the selection and development of leaders for first and second-level managerial positions.     

A NOTE ON MODELING PROJECT INTERDEPENDENCE IN RESEARCH AND DEVELOPMENT*

This note is concerned with the problem of resource allocation under uncertainty in a research and development laboratory. A distinction is defined between project interrelationships that are specific (or internal) to certain projects and interrelationships resulting from external environmental factors. Formulations are introduced that allow both types of interrelationships to be formally included in a resource allocation optimization model. In the case of external environmental factors, an example is presented and analyzed.     

MANAGING YOUR DOCTORAL PROGRAM: A PRACTICAL ORIENTATION

In this article we pass on advice for getting through a dissertation that we found useful in our roles as dissertation advisors and doctoral students. We have also included some other hints on starting and getting through a doctoral program, as well as beginning an academic career. We hope that readers in a position to advise Ph.D. students will convey the recommendations stated here to their students. Since the final responsibility for completing the degree rests with the student, the advice given here is, by and large, addressed directly to students and can be passed on to them in its current form.