Industry leaders are optimistic about the great success of service-oriented architecture (SOA) in realizing adaptive, real-time, and on-demand enterprises. Services have emerged as the proven construct for rapidly implementing and sustaining mission-critical, enterprise-scale business systems. They provide the most efficient units for realizing business realities and requirements. Services are publicly addressable, discoverable, accessible, and manageable. In addition, they are interoperable and reusable.