Optimizing multi-stage production with constant lot size and varying numbers of batches

The model presented in this paper assumes that a uniform lot size is produced through a series of manufacturing stages, with a single set-up and without interruption at each stage. Transportation of partial lots, called batches, is allowed between stages after the whole batch is completed. The batch sizes must be equal at any particular stage, but the optimal number of equal-sized batches may differ across stages. Of course, the set-up costs, the inventory-holding costs and the transportation costs influence both the optimal batch-sizes at the various stages and the uniform lot size. An optimization method for this deterministic model is developed and is illustrated by an example.     

Revisions of the Fish Invasiveness Screening Kit (FISK) for its Application in Warmer Climatic Zones,with Particular Reference to Peninsular Florida

The initial version (v1) of the Fish Invasiveness Scoring Kit (FISK) was adapted from the Weed Risk Assessment of Pheloung, Williams, and Halloy to assess the potential invasiveness of nonnative freshwater fishes in the United Kingdom. Published applications of FISK v1 have been primarily in temperate‐zone countries (Belgium, Belarus, and Japan), so the specificity of this screening tool to that climatic zone was not noted until attempts were made to apply it in peninsular Florida. To remedy this shortcoming, the questions and guidance notes of FISK v1 were reviewed and revised to improve clarity and extend its applicability to broader climatic regions, resulting in changes to 36 of the 49 questions. In addition, upgrades were made to the software architecture of FISK to improve overall computational speed as well as graphical user interface flexibility and friendliness. We demonstrate the process of screening a fish species using FISK v2 in a realistic management scenario by assessing the Barcoo grunter Scortum barcoo (Terapontidae), a species whose management concerns are related to its potential use for aquaponics in Florida. The FISK v2 screening of Barcoo grunter placed the species into the lower range of medium risk (score = 5), suggesting it is a permissible species for use in Florida under current nonnative species regulations. Screening of the Barcoo grunter illustrates the usefulness of FISK v2 as a proactive tool serving to inform risk management decisions, but the low level of confidence associated with the assessment highlighted a dearth of critical information on this species.     

Sourcing Strategy,Supplier Relationships and Firm Performance: An Empirical Investigation of UK Organizations

This article conceptualizes and empirically examines buyer–supplier relationships in respect of supply sourcing strategies, relationship characteristics and firm performance. Two sourcing strategies available to organizations are examined, critical and leverage, which in turn, influence the approach to managing the supplier relationship (arms‐length or collaborative). We argue that different relationship approaches are appropriate to achieving different performance outcomes. A structural equation model, using a sample of 142 manufacturing firms based in the United Kingdom, is used to test this hypothesized model. The results indicate that a critical sourcing strategy requires collaborative supplier relationships in order to achieve higher relationship and business outcomes, while leverage sourcing strategies have a direct impact on these same performance outcomes. In addition, a leverage strategy was associated with increased levels of supplier power, though this power was found not to have a significant effect on performance. Our study provides support for the importance of aligning sourcing strategies to particular supplier relationship approaches in order to improve firm performance. Managerial implications of these findings and future directions for research are then offered.     

The Effect of Socialization Mechanisms and Performance Measurement on Supplier Integration in New Product Development

This article examines the effect of socialization mechanisms and supplier performance measurement on the level of supplier integration in new product development and subsequent firm performance outcomes. Prior research has found socialization mechanisms and performance measures to be effective in managing supplier relationships, though research examining their impact within a product development context has been limited. Socialization mechanisms, such as supplier conferences and on‐site visits, help establish communication and information‐sharing routines necessary to achieve supplier integration in the product development process. Using performance measures to evaluate a supplier helps focus managerial attention on areas such as innovation and communication that are important to integration success. A structural equation model, using a sample of 142 manufacturing firms based in the United Kingdom, indicates that the level of supplier integration in new product development is positively influenced by socialization mechanisms and innovation‐focused measures of supplier performance, but not significantly associated with the use of communication measures. In turn, increased levels of supplier integration led to improvements in both collaboration outcomes and business performance. Socialization mechanisms were also found to have a direct effect on collaboration outcomes achieved by the firm. Managerial implications and future research directions are discussed.     

Perspectives on Regional and Enterprise Marginality: Dairying in Michigan's North Country1

Abstract Dairy farmers in Michigan's Upper Peninsula, an economically marginal rural region, are encumbered by contextual constraints that are not similarly faced by their downstate counterparts. However, this does not mean that they are any less ambitious or less efficient in dealing with the resources available to them. Indeed, dairying and similar small-scale economic enterprises in this and other marginal contexts may be quite competitive and sustainable if appropriate sociopolitical supports are instituted and, in the case of dairying, if marketing orders and regulatory policies are formulated and implemented in light of their impact upon the economic growth and viability of the wider region. To explore this issue, we consider the situations, basic characteristics, and restructuring trends over time of dairy farms in three upstate localities as compared with that of a downstate dairy farming community.     

Pensions and job search: Survey evidence from unionized workers in canada

Research on the disincentives for quitting under employer-sponsored pension plans have limited generalizability as tests of the implicit contract thesis because of the way that job changing, pension back-loading, and plausible alternative explanations for pension effects have been operationalized. Using a unique data set that addresses some of these concerns, I find that pension back-loading and insecurity about the viability of a long-term employment contract are quantitatively the most significant determinants of job search intentions, followed by other seniority related benefits, such as vacation pay and shared investments in firm-specific training. No support for pension information, wage tilt, or efficiency wage arguments is found. Males and the better educated are also more likely to intend to search. Implications for theory, policy, and future research are discussed. I thank Morley Gunderson for helpful comments made on an earlier draft of this paper. Financial assistance from the Social Sciences and Humanities Research Council is gratefully acknowledged.     

Rail safety and rail privatization

Privatisation of the state-owned British railway system was completed in 1997. The following 6 years saw four serious fatal train accidents, leading to 49 deaths. These were the train collisions at Southall in 1997 and Ladbroke Grove in 1999, each caused by trains passing red signals, and the derailments at Hatfield in 2000 and Potters Bar in 2002, each caused by defective track. Has safety been compromised by the sell-off of the railways? Andrew Evans looks at the evidence and asks has privatisation led to more accidents?     

Japanese labor relations during the twentieth century

The author ofThe Evolution of Labor Relations in Japan (1985).