The Web service orchestration enables cross departmental coordination of business processes in a heterogeneous environment. We have designed a component-oriented web service orchestration based on service functionality in an Enterprise Service Bus (ESB). Our orchestration model is centralized-base, where a single service is the central coordinator containing the composition logic of the other services involved. These services are modelled using Service Component Architecture (SCA) specification, deffined in our UML profile described in this paper. SCA conforms to SOA (Service Oriented Architecture) principles using CBSE (Component-Based Software Engineering) techniques. Finally, our specified orchestration model is implemented using Model-Driven Architecture Approach (MDA).