摘要:Service Oriented Architecture (SOA) introduced the web services as distributed computing components that can be independently deployed and invoked by other services or software to provide simple or complex tasks. In this paper we propose a novel approach to solve the problem of the business processes execution engine web service selection and services composition in the Service Oriented Architecture (SOA) related to the Synchronous mode. The paper provides a mechanism to improve the web services selection and service composition, using dynamic web services and service composition classification and Simulated Annealing (SA) to satisfy services' requirements expressed as the Service Level Agreement (SLA). The results show that the proposed approach enhanced the services composition by increasing the availability and decreasing the response time to the service composite.