A system and method for facilitating reuse of a portion of process logic by different processes. An example method includes providing a subprocess that is adapted to perform the process logic in a file accessible to a composite system, wherein the subprocess is adapted to be called by a first parent process via a subprocess extension to a business process language employed to encode the first parent process; using a call activity defined as part of the subprocess extension, and included in a scope of the first parent process to facilitate access to functionality of the subprocess by the parent process; and employing a business process engine to facilitate instantiating the subprocess, resulting in an instantiated subprocess in response thereto; and using a second parent process to share use of the instantiated subprocess with the first parent process.