A system for composing Web services may include a goal determiner unit and a composer unit. The goal determiner unit may be configured to access a primary goal of final states of Web service representations. The composer unit may be configured to compute a set of transitions from initial states of the Web service representations to the primary goal, compute intermediate states of one or more Web service representations, and generate a copy rule of the set of transitions, the copy rule having a condition part that specifies the intermediate states and a portion of the final states of the primary goal and an activity part that includes assignments of input variables consumed by transitions from the intermediate states.