ERPs are one of the fastest-growing segments of the business-software industry. They offer a single system linking together all corporate operations, including planning, manufacturing, sales, vendor relations, inventory control, human resources, and accounting. Companies around the world spent over $10 billion on ERPs last year. Like many new technologies, ERPs have near-magical effects when they work as promised. Companies have reported, for example, the ability to calculate new prices instantly when a single component in a product changes; more accurate manufacturing cost comparisons among different facilities; better electronic data interchange (EDI) with vendors and suppliers, etc. However, ERP installations don’t always go smoothly. This article offers tips from those who have lived through the experience. Includes a sidebar on planning tips on designing and implementing an ERP program.