“Just-in-time” manufacturing has become one of the bedrock techniques of American industry – a system where plants keep as few spare parts as possible in stock, instead ordering them just as they’re needed, like a bucket brigade fighting a fire.

But with the year 2000 on the horizon, some experts are concerned about the weakness of just-in-time systems: Problems at one small supplier can ripple through the chain, creating tie-ups for dozens of other businesses.