Sub-Processes

A Sub-Process (Nested Business Process) is an independent business process initiated during the execution of the parent process. When a sub-process is initiated, ELMA suspends the execution of the parent process until the sub-process is completed. The only exception is the external sub-process with the "Multiple Execution" marker.

Sub-processes are used in business process modeling for decomposition. This approach allows you to break down one large task into a series of smaller tasks. Decomposition is needed when a process model turns out too complex and hard to read, or if there is a sequence of actions in the process that can later be used in other business processes.

Any sub-process has its own properties, such as graphic model, responsibility matrix, metrics and KPIs, forms, scripts, versions and policies. However, sub-processes differ by how their context and data exchange are managed:

External Sub-Process is a business process executed in its own context. It passes data to the parent process via the input and output process attributes, scripts, and Send Message and Receive Message activities. You can start an external sub-process as an independent process.
Internal Sub-Process is a business process executed in the context of the parent process. It belongs to the parent process and therefore uses the data stored in the parent process. Though an internal sub-process is executed within the parent process, it can have its own context variables that exist only within the sub-process. You can start the internal sub-process only within its parent process.


Fig. 1. Internal sub-process in the graphic model.	Fig. 2. External sub-process in the graphic model.