BPEL

The exact details of business processes can be specified by executable processes. These can be executed by orchestration engine. An executable process is used in most cases of BPEL.

The public message exchange among parties is only allowed by abstract business process. The internal details of process flows do not include and are not executable.

Choreography does not rely on a central coordinator. The web services involved in the choreography is aware exactly the execution of its operations and whom to interact with. Choreography is a collaborative effort. It focuses on messages exchange. The awareness of business process, operations to execute, messages to exchange, and the time of message exchange are needed for all participants of choreography.

The BPMN specifies a graphical notation for expressing business processes in a Business Process Diagram. Both technical users and business users are supported for business processes using BPMN. BPMN provides a standardized, simple means of process information communication to other business users, customers, suppliers and process implementers.

BPEL supports two different types of business processes:

★ Executable processesallow us to specify the exact details of business processes. They can be executed by an orchestration engine. In most cases BPEL is used for executable processes.

★ Abstract business protocols allow us to specify the public message exchange between parties only. They do not include the internal details of process flows and are not executable.

There are several methods for incorporating Java and Java EE code in BPEL processes:

★ Wrap as a Simple Object Access Protocol (SOAP) service

★ Use bpelx:exec built-in methods

★ Use Java code wrapped in a service interface

★ Embed Java code snippets into a BPEL process with the bpelx:exec tag

★ Use an XML facade to simplify DOM manipulation