Most US weapon systems enter development and production with much less maturity than wider industry best practices would allow, according to a report by the US General Accounting Office (GAO). This causes technical problems, cost growth and schedule delays, says the Congressional watchdog.

The GAO assessed 26 major defence programmes, and found that all "proceeded with less knowledge at critical junctures than suggested by best practices". The agency assessed technology maturity at the start of development, design stability at the critical design review midway through development, and manufacturing process control at the start of production. The maturity at each stage was compared with that achieved in the best commercial product-development programmes.

Although the report makes no recommendations, it singles out several programmes for criticism, and a handful for praise. The Lockheed Martin Boeing F/A-22 stealth fighter entered development in 1991 with key technologies still immature, the GAO says, and only 26% of engineering drawings had been released by the 1995 design review. Late drawing release contributed to parts shortages, cost increases and flight-test delays. The GAO believes production costs will continue to increase, but the US Air Force argues production cost reductions will keep the programme within budget.

The GAO believes the Boeing Sikorsky RAH-66 Comanche combat helicopter shows promise of being a "best practices" programme, if only because most of the critical technologies have been matured over "many years of difficult development". Delaying the design review to April allowed drawing release to reach the 90% mark, the report says. Despite a generally favourable assessment, the report points out that the time to obtain initial capability has increased from nine years to 21.

The GAO argues that a low-risk entry path to production requires a "knowledge-based" approach, where high levels of product knowledge - measured by technology maturity, design stability and manufacturing process control - are demonstrated at critical points in the development cycle.

Source: Flight International