With top supply-chain performers working twice as efficiently as the average, the potential for improvement is huge. Most companies have a long ride before they catch up to supply-chain exemplars such as Wal-Mart and Dell Computer. Managing inventory is about a lot more than ordering the right software; executives need to get the big issues under control. This article lists the 10 warning signs that tell managers their "supply trains" are running out of control. One example of a danger sign? When managers don't share supply-chain data with partners such as suppliers.