Service-oriented architecture (SOA) has been on the IT buzzword bestsellers' list for as long as any other phrase I can remember. Over the past 10 years, there have been prominent examples of enterprises that have successfully implemented SOAs and have achieved substantial advantages, including reduced costs and improved competitiveness. Unfortunately, such examples are not commonplace because implementing a successful SOA is difficult. However, when successful, the promise and business benefits of SOA are undeniably compelling.