Business processes specified in BPEL will interact with partner processes through operation invocations on Web services. The communication between Web services is USUALLY over internet connections that are not HIGHLY reliable. Web services can also raise faults due to logical and execution errors. Therefore, BPEL business processes need to handle faults appropriately and may also need to signal faults themselves.

Faults in BPEL can be from various sources:

• A BPEL PROCESS can explicitly signal (throw) a fault.
• A fault can occur when the BPEL process invokes a Web SERVICE operation. The operation might return a WSDL fault message, which results in a BPEL fault.
• A fault can be thrown automatically by the BPEL runtime environment, EITHER due to a certain condition in the BPEL process itself (such as a join failure), as a consequence of error conditions in the runtime environment, or related to network communication or other reasons. For such situations, BPEL defines several standard faults.

Business processes specified in BPEL will interact with partner processes through operation invocations on Web services. The communication between Web services is usually over internet connections that are not highly reliable. Web services can also raise faults due to logical and execution errors. Therefore, BPEL business processes need to handle faults appropriately and may also need to signal faults themselves.

Faults in BPEL can be from various sources: