Knowledge that Transforms

Earlier models for the evaluation of assuming and shedding risks of death are extended to the case of possibly extreme disability over a lifetime. Earlier micromort values are supplemented with microdisability values to enable individuals to make consistent decisions in hazardous situations.

The process of converting a tree into finished lumber involves several interrelated steps. The two of greatest potential for improvement are cutting the felled tree into shorter logs (called bucking the tree) and sawing the bucked logs into lumber. Unlike previous work in the area, this paper considers the two activities together as a single production system. The model allows for variations in tree shape and quality which could be recorded by modern electronic scanners. Among the principal techniques used in the paper are dynamic programming for both bucking and sawing, and a procedure for calculating the distance between two polyhedral sets in R 2 . Computational experience is reported on trees with representative defect patterns, taper, and sweep.

Single objective cost minimization linear programming models are used as computerized decision-aids in sausage manufacturing (hot dogs, bologna, salami, etc.). However, sausage blending is clearly a problem with multiple conflicting criteria (cost, color, fat, protein, moisture, etc.) Presented in this paper is a vector-maximum/filtering MOLP (multiple objective linear programming) methodology for use as an improved decision-making approach with single formula sausage blending problems.

This paper investigates a multi-item, multi-level production scheduling problem with linear costs and production and inventory constraints at one key facility. Two multi-item problems—one in which the constraint was on shipping capability and one in which there was a final stage bottleneck machine—motivated the paper. A multi-item facilities-in-series problem is formulated, in standard fashion, as a linear program. Then we show that in certain important cases the 3-period problem is a network problem. This 3-period result is used as the basis for a rolling heuristic for T-period problems. The conditions under which this heuristic fails to find optimal solutions are discussed and computational comparisons to standard linear programming are given. Finally, we discuss ways of dealing with two constrained facilities and with setup costs.

This paper proposes new concepts and new results which could lead to a more realistic preference modeling than in classical decision theory. Sections 1–3 present four fundamental situations of preferences, their combinations and the concept of relational system of preferences. In §4, a particular case of relational system of preference is studied. It is associated with the concept of pseudo-criterion derived from the classical concept of criterion by adjunction of two thresholds. Some results are given, generalizing the properties of such well-known structures as complete preorders and semiorders. Sections 5 and 6 emphasize the possibilities given by the preceding concepts to take the imprecisions, irresolutions and incomparabilities appearing in every concrete problem where several criteria must be considered into account.

We provide worst case error bounds for several approximation methods (heuristics, product aggregation, and partitioning of the planning horizon) for the uncapacitated dynamic lot size problem. We propose two managerially oriented heuristics and show that they have a relative wont case error bound equal to two, and develop similar analyses for methods known as the least cost per unit heuristic, the part period balancing heuristic, and an economic order quantity heuristic (expressed in terms of a time supply of demand). We also show how errors introduced by partitioning of the planning horizon in multi-product multi-facility problems are bounded by product set-up costs, and how errors introduced by product aggregation are bounded by set-up costs, holding costs, and demands. The latter results suggest methods for product aggregation that minimize the worst case error bounds.

This paper seeks to get behind specific contextual referents of risky situations to consider characteristics of risk that apply to many situations. It is guided by previous theoretical and empirical research in perceived risk, and focuses on the joint effects on risk of loss probability and the distribution of losses. The approach taken follows modern axiomatic theory by proposing conditions on a relation “is at least as risky as” between pairs of probability distributions over an outcome variable. Several sets of axioms for risk that characterize different forms for risk measurement are presented.

The factored transportation problem is one having cost coefficients of the form c ij = u i v j . The main result proven in this paper is that if rows are arranged according to nonincreasing u i and columns by nondecreasing v j , then the northwest corner rule provides an optimal solution. Applications to stock location in a warehouse and information storage and retrieval policies are presented. For the stock location problem, this verifies that a previously advocated heuristic is optimal.

In this Note, we address the issue of safety stock considerations in an MRP environment through the use of a single identical component as a replacement for a set of multiple components. We indicate where the results reported by Collier (Collier, David A. 1982. Aggregate safety stock levels and component part commonality. Management Sci. 28 (11, November) 1296–1303.) may prove to be misleading.

Hazard management of the risks of human injury and death related to the automobile are described and exemplified by the Swedish car manufacturer Volvo. The study presents the Volvo units engaged in accident hazard management and their roles in the elaborate system of feedbacks (information, penalties and rewards) created by the company and society for maintaining a high level of automobile safety. Improvements are suggested although the overall quality of the accident hazard management process is considered quite good. Although the study is focused on the automobile industry, it should be regarded as part of a much-needed wider perspective on hazard management applying to other technologies and industries as well. In general, the following factors are considered important to high quality accident hazard management by companies and society: (1) Public concern about safety issues, (2) technological capacity and organizational tradition of safety engineering in the manufacturing company, (3) routines for announcing future proposed safety standards, e.g., US Federal Register, (4) laws enforcing a recall system, (5) annual vehicle inspections and (6) effective product liability laws.