No corporation needs to be convinced that in today’s scale-driven, technology-intensive global economy, partnerships are the supply chain’s lifeblood. Companies, especially in developed economies, buy more components and services from suppliers than they used to. The 100 biggest U.S. manufacturers spent 48 cents out of every dollar of sales in 2002 to buy materials, compared with 43 cents in 1996, according to Purchasing magazine’s estimates. Businesses are increasingly relying on their suppliers to reduce costs, improve quality, and develop new processes and products faster than their rivals’ vendors can. In fact, some organizations have started to evaluate whether they must continue to assemble products themselves or whether they can outsource production entirely. The issue isn’t whether companies should turn their arms-length relationships with suppliers into close partnerships, but how. Happily, the advice on that score is quite consistent: Experts agree that American corporations, like their Japanese rivals, should build supplier keiretsu: close-knit networks of vendors that continuously learn, improve, and prosper along with their parent companies. (Incidentally, we don’t mean that companies should create complex cross holdings of shares between themselves and their suppliers, the way Japanese firms do.)

A version of this article appeared in the December 2004 issue of Harvard Business Review.