There are things we know that we don?t know - the known unknowns. And there are unknown unknowns - the things we do not yet know that we don?t know

- Donald Rumsfeld, U.S. Secretary of Defense Department of Defense is moving rapidly towards Service-Oriented Computing (SOC) recently as evidence of DoD?s projects such as network centric enterprise services (NCES), global information grid enterprise services (GES), and joint battle management command and control (JBMC2). SOC represents a completely new and emerging paradigm of computing instead of thinking in terms of products. Systems will be constructed by reusable services. SOC is different from the traditional computing paradigms as it involves at least three parties in computing: service providers, service consumers, and service brokers.