Introduction to Standalone and Inline BPEL Subprocess Invocations

BPEL provides limited support for modularizing business process logic for reusability. The only method is to package reusable process logic as completely separate processes, which are utilized by the parent process (the process utilizing the reusable process logic) in a method identical to using a web service (through the invoke activity).

To address this challenge, Oracle SOA Suite provides a subprocess extension to BPEL. A subprocess is a fragment of BPEL code that can be reused within a particular processor by separate processes. The subprocess extension provides the following benefits:

BPEL process code reusability, which reduces the need to create the same activities multiple times to perform the same tasks.
Code modularity.
Code maintenance (changes are propagated, which eliminates the need to implement updates in multiple places every time a change is necessary).
Less overhead than invoke activities.
Memory footprint reduction, which can be considerable in a complex process.

Note:

Subprocesses are only supported with BPEL version 2.0. There is no support with BPEL version 1.1.
Correlation sets are not supported in subprocesses. If you create a correlation set in an inline or standalone subprocess, it fails during runtime.
Subprocesses cannot be shared between multiple composites.
Monitor view is not supported from inside a subprocess. Monitor view is accessible from a BPEL process by selecting the Change to Monitor view icon above Oracle BPEL Designer.

Oracle SOA Suite provides support for two types of subprocesses, as described in Table 40-2.

Table 40-2 Subprocess Types

Standalone Subprocess	Inline Subprocess
A BPEL call activity invokes the subprocess.	A BPEL call activity invokes the subprocess.
Supports subprocesses in the same composite only.	Part of the parent BPEL process code and not visible in the composite view.
Visible in the Components window.	Visible in the Components window.
Does not have an interface and can only be called from another BPEL process. It can include partner links.	Subprocess code is re-entrant and reusable at runtime:. Only one copy is stored in memory, even if called many times.
A fragment of a BPEL process that includes a number of activities that are reused across other BPEL processes.	For groups of activities that are reused within one BPEL process.
In the composite view, the wire to a subprocess is shown as a dotted line to indicate that this is not a wire between actual components.	Can either define parameters to set or can use the process parameters.
Not Applicable.	Activities must be in a scope activity to be converted into a subprocess.
For information about creating a standalone subprocess, see How to Create a Standalone BPEL Subprocess.	For information about creating an inline subprocess, see How to Create an Inline Subprocess.