This paper describes a methodological step for the construction of process specifications in the M*-OBJECT information system design methodology. The process construction integrates an object-oriented approach to the specification of system components with a set of composition rules for the integration of components' behavior. First of all, the Process and Data Net (PDN) model (which is the basic specification tool of the M*-OBJECT methodology) is briefly illustrated. The PDN model integrates the representation of static, dynamic, and behavioral aspects of a database application, and it is based on an object-oriented data model and a process model. The first is used to describe static and behavioral aspects of objects which represent system components, while the latter describes in which way organization activities are co-ordinated. Then the co-ordination method for behavior composition is specified. It starts from the nets which describe the communications and the control of the classes that represent the system components involved into the process, and constructs the executable specification of the same process.
