Nowadays, novel applications, such as personalized e-commerce services, call for cooperation across enterprise boundaries. Service-Oriented-Architecture (SOA) forms a solution to build loosely coupled distributed applications by composing Web services that are provided by different entities. Orchestration is a perspective of Web service composition. The traditional approach to implement orchestration is to use an executable language such as WS-BPEL to express a workflow. However, it has some undesirable drawbacks due to its static nature. This paper explores an unconventional approach known as chemical programming on expressing workflow and service orchestration. It has some valuable characteristics such as automated, dynamic and parallel execution which enable it to be a competitive candidate for service composition.