Users need to be strongly involved in the specification process of network information systems. Characteristics of user-driven specification are described, and process composition is proposed as a feasible approach. The knowledge representation framework used in the RENISYS specification method is introduced, using conceptual graph theory as its underlying formalism. The role of ontological and normative knowledge is explained. The presented theory is used to show how legitimate process definitions can be generated by the users. The facilitation of user-driven process composition is discussed.