Service Oriented Architecture provides an effective application integration and on-demand services provision. It supports loose coupling structure of the services which provides effective service management and also effective usage of the existing services. SOA gives strong support to business Innovation if implemented properly with proper understanding of the Principles of SOA. In order to incorporate the effective SOA, there should be a thorough deployment of the SOA, the SLA metrics needs to be standardized and focused. Since, the reliability of any service depends on the successful functionality. This article studies and reviews on a broad spectrum the Service Oriented Architecture and its Service Level Agreement (SLA) and its basic metrics.