Mechanisms for kilometre‐scale, open‐system fluid flow during regional metamorphism remain problematic. Debate also continues over the degree of fluid flow channellization during regional metamorphism, and the mechanisms for pervasive fluid flow at depth. The requirements for pervasive long‐distance fluid flow are an interconnected porosity and a large regional gradient in fluid pressure and hydraulic head (thermally or structurally controlled) that dominates over local perturbations in hydraulic head due to deformation. In contrast, dynamic or transient porosity interconnection and fluid flow accompanying deformation of heterogeneous rock suites should result in moderately to strongly channellized flow at a range of scales, of which there are many examples in the literature. Classification of fluid flow types based on scale and degree of equilibration between fluid and rock, wallrock permeability, and mode of fluid transport contributes to an understanding of key factors that control fluid flow. Closed‐system fluid behaviour, with restricted fluid flow in microcracks or cracks and limited fluid–rock interaction, occurs over a range of strains and crustal depths, but requires low permeabilities and/or small fluid fluxes. Long‐distance, open‐system fluid flow in channels is favoured in heterogeneous rocks at high strains, moderate (but variable) permeabilities, and moderate to high fluid fluxes. Long‐distance, broad, pervasive fluid flow during regional metamorphism requires that the rocks are not accumulating high strains and have high permeabilities, low permeability contrasts, and high fluid fluxes. The ideal situation for such fluid flow is in situations where the rocks are undergoing stress relaxation immediately after a major deformation phase. In the mid‐crust, fairly specific conditions are thus required for pervasive fluid flow. During active orogenesis, structurally controlled fluid flow (with focused open systems surrounding regions of closed‐system behaviour) predominates in most, but not all, regional metamorphic situations, at a range of scales.

This paper reports managerial views of the responsibilities of teams, team members and functional specialists under lean production, based on the findings of an international study of management practices in the automotive components industry. The findings show limited evidence of shopfloor worker autonomy under lean team-working or of increases in technical skill; blue-collar specialists remain responsible for maintenance activities. However, the Taylorist separation of planning and execution appears to be partially reversed as operators are expected to make significant contributions to problem solving, innovation and improvement activities. Personnel issues remain largely the prerogative of senior management and white-collar specialists. The role of middle managers appears to be `hollowed out' as shopfloor employees, particularly team leaders, take more responsibility for some activities. The findings emphasize the importance of distinguishing between the roles of members and leaders within teams, and between the responsibilities of production teams and those of other occupational groups.

This paper documents the adoption of the Japanese model of manufacturing in the U.K. motor industry. Internal developments by the vehicle assemblers and their suppliers are examined. It is argued that the Japanese model involves very high intra-and interorganizational dependencies. Although thk does not cause problems in Japan due to the structure of the Japanese motor i n h t t y , the structure of the UK vehicle industry presents severe obstaclesto the successful use of Japanese methods. Pursuit of the pure Japanese model within the existing industry structure appears to be fraught with problems. Moreover, such an exercke risks sweeping away potential strengths of the exikting structure.

This paper examines the manufacturing performance and management practices of 71 automotive components suppliers located in Europe, Japan and North America. The research reports on the extent to which these plants have adopted 'lean production' practices and tests the proposition that such techniques are linked with high manufacturing performance. The results support the contention that tight process control and closely integrated operations are more productive. However, the data do not support the notion that the

The control of fluid flow by plastic deformation during metamorphism is critical to our understanding of metamorphic processes. Various geological observations and field studies demonstrate the consequences of fluid flow control by deformation, so that the concept appears to be accepted, at least for small-scale systems (for example faults and vein systems). However, the concept appears to be less well recognized at regional scales. Considered here are examples of simple, conceptual models based on fully coupled mechanical-fluid flow concepts; they include deformation of a section of fluid-saturated crust containing a block or a layer of material of different properties from its surrounds. In particular, rheological and permeability contrasts between rock types during deformation associated with regional metamorphism are sufficient to control the form of fluid flow over the range of a few kilometres. Low contrasts and small strains allow pervasive fluid flow, whereas greater contrasts and increasing strains cause focusing of the flow. Such focusing is generally associated with localization of the deformation, especially for a strongly dilatant elastic-plastic material. However, a rate of fluid flow much greater than the rate of deformation may result in pervasive flow, although for most models pervasive flow is difficult to attain over regional distances. Furthermore, lateral and downward fluid flow may occur, demonstrated here by simple models for folding and for deformation of regions containing plutons. Therefore, such modelling may be used as a means of testing the various hypotheses concerning the volumes of fluid predicted to have passed through some rock volumes. Numerical models of the future will become increasingly complex and powerful, allowing greater coupling of thermal, mechanical, chemical and fluid flow effects, and based more on the physical processes involved. Combined field and laboratory studies will provide correspondingly greater understanding and will permit the determination of the timing of fluid flow and structural controls on fluid flow patterns.