OPERATING POLICIES FOR SCHEDULING ASSEMBLED PRODUCTS

This paper describes a simulation study of the relative impact of different operating policies on performance of a hypothetical multistage production system that produces assembled products. The main objective of this study is to examine the impact of operating policy rules on system performance. Several performance criteria, including flow time and earliness and tardiness measures, were used to evaluate system performance. Results show that performance of the production system is significantly influenced by the operating policy rules, although the relative impact of the rules is dependent on the performance measure considered. Interactions between and among policy rules were also found to be important in several cases. Overall, the results indicate that much previous research in non-assembly systems can be generalized to assembly systems. Subject Areas: Scheduling, Material Requirements Planning, and Simulation.     

THE STRUCTURE OF EXECUTIVE INFORMATION SYSTEMS: AN EXPLORATORY ANALYSIS

This paper reports on a study which attempted to identify the structure of executive information systems and evaluate their relationship to decision making. The study centered on answering the question: “Where and how do senior executives get their decision-making information?” The data, provided by five senior executives, were gathered by a variety of means which included personal interviews, questionnaires, and logs of the executives' incoming-information transactions for a two-week period. Our findings support beliefs that senior executives receive much information from the environment, that informal systems play a role equal to that of formal systems, and that computers do not provide much information directly to an executive. The study also found that internal information is important and that preferred sources and media vary with different decision roles. The authors suggest that the scope of MIS and DSS be broadened to match those information networks managers actually rely on in daily practice.     

Setup Reduction in the Economic Production Quantity Model

We present an analysis of setup cost reduction using the economic production quantity model. The objectives of the paper are to draw conclusions by investigating several classes of setup reduction functions and to provide a general solution procedure. We examine the trade-offs between reduced inventories and increased capital investment and show that given any hypothetical setup cost reduction function, we can determine whether the total relevant cost can be reduced and how the reduction is achieved.     

MODELING DEMAND DURING LEAD TIME*

This paper treats some of the important considerations in constructing an analytical model for the distribution of demand during lead time. It presents a formal model that can be developed along one of two lines. The first has order size and order intensity leading to a compound distribution of period demand, then period demand and lead time giving rise to a compound distribution of demand during lead time. The second has order intensity and lead time giving rise to a compound distribution of lead-time order intensity, then lead-time order intensity and order size leading to a compound distribution of demand during lead time. The paper also condenses the state of the art in a table and proposes some simple classification schemes that could help researchers extend that state of the art.