پیاده سازی ناب در هوا و فضا— به چالش کشیدن مفروضات و شناخت چالش
|کد مقاله||سال انتشار||تعداد صفحات مقاله انگلیسی||ترجمه فارسی|
|10704||2003||12 صفحه PDF||سفارش دهید|
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Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Technovation, Volume 23, Issue 12, December 2003, Pages 917–928
Lean manufacturing appears to hold considerable promise for addressing a range of simultaneous, competitive demands including high levels of process and product quality, low cost and reductions in lead times. These requirements have been recognised within the aerospace sector and efforts are now well established to implement Lean practices. Lean manufacturing was initiated within the automotive sector. However, since the publication of the influential book, The Machine That Changed the World (Womack et al., 1990) there has been a range of documented cases of Lean implementation in a variety of sectors. Despite this evidence, the perception remains that Lean manufacturing is to some degree, an ‘automotive idea’ and difficult to transfer to other sectors especially when there are major differences between them. In this paper we discuss the key drivers for Lean in aerospace and examine the assumption that cross-sector transfer may be difficult. A Lean implementation case comparison examines how difficulties that arise may have more to do with individual plant context and management than with sector specific factors.
Manufacturing has undergone radical and fundamental changes over the past decade. The relatively ‘static’ nature of market conditions within the mass production era have now been replaced by market requirements that are profoundly different to mass production. The terms used to describe the current era include: • Mass Customization (Pine et al., 1993)—reflecting the need for volume combined with recognition of customers’ (or ’consumers’) wishes. • Flexible Specialization (Piore and Sabel, 1984)—related to the manufacturing strategy of firms (especially within small firms) to focus on parts of the value-adding process and to collaborate within networks in order to produce whole products. • LeanProduction (Womack et al., 1990)—developed from the massively successful Toyota Production System, focusing on the removal of all forms of waste from a system (some of which are difficult to see). • Agile (Kidd, 1994) emphasising the need for an organisation to be able to switch frequently from one market-driven objective to another • Strategic ( Hill, 1995 and Brown, 1996) in which the need for the operations to be framed in a strategy is brought to the fore. Whatever term is employed, the paradigm for the current era is, as mass production was a hundred years ago, a major innovation process that makes the system it replaces, largely redundant. Time-to-market and product customization are now high on the strategic agenda (Clark and Fujimoto, 1991, Hart and Berger, 1993, Pine et al., 1993 and Sasaki, 1991). Perhaps the most popular term to describe the current era is that of Lean production. This developed from the book, The Machine That Changed the World, in which the authors examined the Toyota Production System and provided data on Lean and non-Lean plants within the automotive industry (Womack et al., 1990). Lean production describes the Japanese-style manufacturing process pioneered by Toyota, which uses a range of techniques including just-in-time inventory systems, continuous improvement, and quality circles (Krafcik, 1988). Lean is concerned not only with the firm’s internal manufacturing capabilities, but is also heavily dependent upon supplier involvement within the supply network ( Levy, 1997 and Oliver et al., 1996). The essential characteristics of Lean production include the following factors: • Integrated production, with low inventories throughout, using Just-in Time management; • Emphasis on prevention, rather than detection in quality; • Production is pulled in response to customers, rather than pushed to suit machine loading or other in-house ideas of scheduling; • Work is organized in teams, using multi-skilled workforce problem solving to eliminate all non added value (Dankbaar, 1997); • Close vertical relationships, integrating the complete supply chain from raw material to customer. The claims of the authors of The Machine That Changed the World were both bold and clear. Ultimately, it is claimed, Lean practices will spread to all manufacturing: ....the adoption of Lean production, as it inevitably spreads beyond the auto industry, will change everything in almost every industry—choices for consumers, the nature of work, the fortune of companies, and, ultimately, the fate of nations (Womack et al., 1990:p. 12) and ...we believe, Lean production will supplant both mass production and the remaining outposts of craft production in all areas of industrial endeavor to become the standard global production system of the twenty-first century (Womack et al., 1990, p. 278). Undoubtedly, as Womack et al. (1990) predicted, Lean practices have crossed from the automotive sector into other industries. However, the Lean paradigm is not without its critiques. For example, Delbridge (1998) is very critical of supposed benefits of team working and empowerment promised by the adoption of Lean practices and argues that these are based on myth. These views have some support in the aerospace sector, as the following quote illustrates: “Lockheed’s version of Lean manufacturing isn’t with employee empowerment”, says Terry Smith, a business representative with the International Association of Machinists and Aerospace Workers (LAM) at the Ft. Worth plant. “Their version of Lean manufacturing is more top down where they say, ‘We want you to do it this way so we can figure out how to do it cheaper and with less people’”Manufacturing News. (April 10, 2000 p. 3) Despite some criticism with Lean, the Aerospace sector has recognised the opportunity to eliminate huge amounts of waste within its value streams and the Lean ‘revolution’ within the industry is clearly underway, as the following indicates: The aerospace industry is in the grip of a revolution. Its name is ‘Lean’ and its guiding principle is the elimination of waste from the production cycle. The revolution is moving out of the prototyping shops and on to the assembly lines, with dramatic results—and none too soon. The automotive industry has been Lean for years. In aerospace, avionics and engine manufacturers embraced Lean thinking long before the airframe makers. Now airframers are moving fast to catch up. Their motivation is the promise of faster development, better quality and lower cost” Flight International. (Sept, 1999) This is endorsed by Cook (1999) when he states: Lean aircraft designers consider that a new ‘right first time’ culture in aerospace manufacturing will do for aircraft what it did for the car industry a decade ago. Under the new regime, panels and components damaged in operation can be quickly replaced at the front line without special customization in much the same way that car parts are ordered up and fitted in the commercial world. Employees involved in all aspects of Eurofighter production—from the design stage through to logistic support—are grouped in integrated product teams (IPTs). Each IPT is responsible for its own budget and accountable for its particular section of the aircraft (Cook, 1999). The adoption of Lean practices are evident in the US and UK. In the US, Lockheed Martin’s Aeronautics Sector declared 1999 as the ‘year of Lean and is rigorously applying Lean techniques to the F-16 and F-22 fighter programmes and the C-130J military transport aircraft. In the UK, BAE Systems’ military aircraft plants have been heavily involved in employing Lean practices within their businesses in recent years. The Samlesbury site became the company’s flagship manufacturing site, believing that Lean manufacturing was central to controlling costs on the Eurofighter programme. However, BAE Systems perceives that the aerospace industry is 10–15 years behind the automotive sector in implementing Lean ideas (Flight International, Aug–Sept, 1998). Lean ideas are now being transferred throughout the UK aerospace industry, with major initiatives also underway in many manufacturing firms including Airbus UK, Rolls-Royce plc, Smiths Aerospace, and TRW Aeronautical Systems among others. Lean improvement efforts are also being supported in both the USA and UK by national research programmes exemplified in the US Lean Aerospace Initiative at Massachusetts Institute of Technology (MIT) and the UK Lean Aerospace Initiative, a consortium consisting of the Universities of Warwick, Bath, Nottingham and Cranfield. Thus far we have provided a brief introduction of the adoption Lean practices within the aerospace sector. In the following sections of this paper we examine the key drivers for Lean implementation in the Aerospace industry and we then proceed to challenge some of the pre-conceptions of Lean implementation. Lastly, we present our primary data and identify the challenges faced by individual companies through case study comparison.
نتیجه گیری انگلیسی
From our research it would appear that the problems of implementing Lean within aerospace are not, necessarily, more difficult than that of implementing Lean within high volume sectors, including automobiles. The challenges are different but not more difficult. We offer key conclusions from our findings and tentative lessons for other companies can be drawn from the experience of the two sites. First, Lean capabilities are not merely firm-specific but are, instead, plant specific. There were differences in the rate of progress made and differences in the approach taken to Lean implementation. Second, it cannot be assumed that the characteristics of the ‘best performing’ site within a firm that has multiple plants will, necessarily, be transferred to other plants within the same company. Techniques, including benchmarking between sites may help but there needs to be ‘Lean Champions’ between sites if Lean practices are to be disseminated among plants within the same firm. Third, in order for Lean to be implemented, plant-specific manufacturing strategies have to be in place that are comprehensive and holistic in scope and content. Results may also be achieved more readily when improvement activities focus on all or a large part of an identified ‘product value stream’ rather than on a functional area which produces a range of products. Similarly, faster results seem to be possible when process ownership has been established rather than several products sharing production processes. Plant-specific strategies have to include internal targets as well as the development of supplier relationships with external partners. The strategic approach taken to Lean implementation would seem to have a significant impact on the rate of performance improvement (Crute and Graves, 2001). Within the case studies presented, a targeted and holistic approach to Lean implementation delivered faster results in Lean implementation. This approach involves creating a ‘Lean system’ rather than simply applying single Lean techniques. Complementary objectives are set which support the elimination of waste and flow of value to the customer. Such objectives include identifying and eliminating non-value adding activities from your processes; reducing lead times; inventory reduction and establishing ‘pull’ systems. Clear targets and performance measures would also seem to play a critical role in Lean implementation. Fourth, operations managers have to be willing to take on a more strategic role than has been the case in past manufacturing paradigms. This is a difficult issue because the emergence of Lean Production has emerged from the profound changes of manufacturing processes over time. However, as Brown (2000) found, the transition from craft through mass production to the current era of Lean often resulted in operations management being absent from the most senior levels of the firm as enterprises became larger and more organized around functions and although there has been increasing importance placed on operations personnel in terms of their contribution to the firm’s capabilities, including Lean production (Womack et al., 1990 and Kenney and Florida, 1993) this has not included discussion about their involvement in terms of their position at strategic levels within the hierarchy of the firm. Our findings indicate the need for operations managers to have a strategic and not merely tactical role if Lean implementation is to be successful. Senior management have an important role to play in presenting a coherent vision for their business, clearly communicating business strategy and indicating how the Lean philosophy and practices fit with the needs of the business. There also needs to be an awareness of the impact of the consistency of senior management messages. Questions need to be asked concerning whether the philosophies and initiatives being promoted are consistent, timely and necessary. Fifth, our findings indicate that it is possible that Lean implementation can be achieved more rapidly in plants where the culture supports autonomous working and learning through experimentation. Where such a culture does not exist, senior managers will play a key role in creating a context where change is possible. This requires leadership and a consistent message of support. As one interviewee at Site A stated, ‘you need to believe in people and let them try. If they mess it up, support them, and if they mess it up again—support them again’. Sixth, some aspects of improving performance such as changing factory layout require time and physical space to be available, if significant results are to be achieved. Interviewees at the improvement sites suggested that consideration should be given to creating a temporary ‘buffer’ of time through use of evenings or weekends, through committing extra resources to the area or through temporarily increasing stock to ‘make space’ for improvement activities without affecting production demands. Finally, we recognise that a basic definition of any case study is that it is ‘the intensive examination of a single instance of a phenomenon’ (Kervin, 1992, p. 53). By their very nature, case studies may be seen as having limitations is the ‘transferability’ of the findings to other settings. However, we hope that our research will encourage further exploration of the transfer of Lean practices within the aerospace sector including a larger range of case studies as well as multiple sites within the same company.