Production planning under dynamic product environment: a multi-objective goal programming approach

Production planning is a complicated task that requires cooperation among multiple functional units in any organization. In order to design an efficient production planning system, a good understanding of the environment in terms of customers, products and manufacturing processes is a must. Although such planning exists in the company, it is often incorrectly structured due to the presence of multiple conflicting objectives. The primary difficulty in modern decision analysis is the treatment of multiple conflicting objectives. A formal decision analysis that is capable of handling multiple conflicting goals through the use of priorities may be a new frontier of management science. The objective of this study is to develop a multi objective goal programming (MOGP) model to a real-life manufacturing situation to show the trade-off between different some times conflicting goals concerning customer, product and manufacturing of production planning environment. For illustration, two independent goal priority structures have been considered. The insights gained from the experimentation with the two goal priority structures will guide and assist the decision maker for achieving the organizational goals for optimum utilization of resources in improving companies competitiveness. The MOGP results of the study are of very useful to various functional areas of the selected case organization for routine planning and scheduling. Some of the specific decision making situations in this context are: (i). the expected quality costs and production costs under identified product scenarios, (ii).under and over utilization of crucial machine at different combinations of production volumes, and (iii). the achievement of sales revenue goal at different production volume combinations. The ease of use and interpretation make the proposed MOGP model a powerful communication tool between top and bottom level managers while converting the strategic level objectives into concrete tactical and operational level plans.

Flexible automation and the loss of pooling synergy

This paper focuses on the effects of flexible automation on the performance of a job shop. Flexible automated machines may significantly improve the delivery performance and the flow time of jobs. The insertion of a flexible automated system in a job shop, however, also has a counter effect on the manufacturing performance. This is caused by the reduction of pooling synergy due to the dedication implied by flexible automated machines. This paper investigates by means of a simulation study to what extent the loss of pooling synergy will deteriorate job shop performance. Simulation is also used to indicate the level of efficiency of the automated machinery needed to overcome the negative effect of the loss of pooling synergy. The simulation study also highlights the importance of appropriate off-line assignment rules, which assign jobs to either the conventional or automated machines. Major conclusion of this paper is that the ‘pooling loss effect’ should be taken into account in the design and justification of new flexible automated machinery. The design of appropriate offline assignment rules, furthermore, has to be seen as an integral part of investment in new technology.

Thomas Hobbes: theorist of the law

This short article introduces the papers that follow on the topic of Hobbes as a theorist of the law. It provides an overview of Hobbes reputation as a theorist of law in both domestic and international theory. The paper summarizes the papers that follow and suggest how they fit into the wider literature on Hobbes, legal theory, and constitutional theory.PostprintPeer reviewe

The inconvenience of the legislator’s two persons and the role of good counsellors

I focus on Hobbes’s distinction between the natural and political persons embodied in one sovereign and show that, driven by their passions, ignorance, or bad judgement, rulers qua natural men may undermine the end they ought to pursue qua political actors, namely the protection of the well-being of the people. In particular, as legislators, they may make laws that are unnecessary, or that the people cannot endure, or that give rise to their impatience and discontent. I argue that in Hobbes’s argument, the notion of good counsel provides a safety net against bad commands being issued by rulers. I claim that the process of consultation of good counsellors is an essential component of Hobbes’s understanding of law-making. I suggest that the Hobbesian notions of counsel and counsellor provide a valuable framework to illuminate aspects of contemporary global law-making.PostprintPeer reviewe

Comparação do desempenho de machos e fêmeas Duroc e Pietrain em Teste de Granja

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Agronomia.Duroc e Pietrain são genótipos de suínos utilizados na produção de machos híbridos denominados “terminadores” e têm sido selecionados para aumento da taxa de crescimento, melhoria da conversão alimentar e redução da espessura de toucinho. O objetivo deste trabalho foi comparar o peso ao nascer, o ganho de peso diário, o consumo médio diário de ração, a conversão alimentar e a espessura de toucinho entre machos e fêmeas de suínos das raças Duroc e Pietrain submetidos ao Teste de Granja. Análise de dados de um banco de informações de Teste de Granja das duas raças indicou que machos Duroc são mais pesados ao nascer do que machos Pietrain e do que fêmeas das duas raças, e apresentam maior taxa de crescimento diário com maior consumo diário de ração. Apresentam, porém, maior deposição de gordura na carcaça e pior conversão alimentar do que Pietrain. Correlações fenotípicas entre ganho de peso diário e conversão alimentar indicaram associação favorável entre as duas características nos dois genótipos. Portanto, para se melhorar a eficiência da produção de suínos em programas que envolvem os dois genótipos, a seleção deve ser direcionada, no mínimo, para aumento da taxa de crescimento e redução da espessura de toucinho.Swine breeding programs frequently use different sire and dam lines in order to improve the efficiency of swine production. Duroc and Pietrain have been use as sire lines and their breeding goals have been focused in the improvement of daily gain, feed efficiency and carcass meat deposition. The aim of this study was to compare the birth weight, daily weight gain, average daily feed intake, feed conversion and backfat thickness between male and female pigs of Duroc and Pietrain breeds submitted to the “On farm Testing”. Analysis of an “On Farm” data bank indicate that Duroc boars and gilts are heavier at birth than Pietrain and grow faster with higher daily feed intake, but present larger backfat deposition and increased feed conversion. Correlation analysis between daily gain and feed conversion indicated better feed efficiency with increased daily gain. Therefore, in order to improve swine efficiency using Duroc and Pietrain as paternal lines, selection programs have to be directed at least to increase daily gain and to decrease backfat deposition