1 引言 军用和商业航天市场正在发生变化。冷战的结束减少了军用产品的需求,增加了从国防现有投资中获取最大效益的紧迫感。商业性航空业的开放迫使产品单价降低,订货量减少,特别是那些过去赚钱的产品,各航空公司都在努力寻找抑制费用的致胜方案。世界经济的广泛不景气已经减少了对这些产品的资金投入,全球的竞争无情地迫使制造者要在降低费用的同时改进质量、可靠性和生产周期。制造者和使用者同样都在寻找对策。 1 Introduction Military and commercial space markets are changing. The end of the cold war has reduced the demand for military products and added a sense of urgency for maximizing the benefits of existing investments in defense. The liberalization of the commercial aviation industry has forced lower unit prices and reduced order volumes, especially for those products that used to be profitable, and airlines are struggling to find ways to reduce costs. The widespread economic downturn has reduced funding for these products, and global competition has mercilessly forced manufacturers to improve quality, reliability and production cycles while lowering costs. Manufacturers and users are also looking for countermeasures.