Pool

In terms of business process modeling, participants of a process, such as companies or departments, are modeled by pools. When dealing with the mapping from BPMN to BPEL, each pool represents a business process.

Internal and external pool

Internal pool refers to the pool that contains the flow objects of the execution process. When drawing a business process diagram for mapping with BPEL, there must be one and only one internal pool. You can create external pools which represent external partners or external process that interacts with the internal pool. Usually, external pools (or participants in business perspectively) are out of the interest for internal process, and hence presented as black box.

Internal and external pools

To define an internal pool, right click on the pool to select Internal from the popup menu.

Set a pool to be internal pool

Partner link types

In every process, partner link types need to be defined. Partner link types define the interaction between a process and the parties. To edit partner link types, right click on the pool and select Open Partner Link Specification... from the popup menu. In the specification dialog box there are four fields you can fill in.

Partner link of pool

Field Description WSDL The WSDL definition where the service needed was defined. Partner Link Type The interaction between the process and pool. My Role For internal pool, specify provider to be my role. For external pool, specify requester to be my role. Partner Role For internal pool, specify requester to be partner role. For external pool, specify provider to be partner role.

Description of fields in partner link specification

Variables

A variable correspond to a message that send to/from partners. It also can be defined for internal logic usage. You need to add variable(s) to internal pool and select the WSDL message type. To add a variable:

1. Right click on a pool and select Open Variables Specification... from the popup menu.
2. In the specification dialog box, click Add... at the bottom of dialog box.
3. Give a name to the variable.
4. Click on the Message drop down menu and select the WSDL message.
   

   Selecting a WSDL message for variable

Correlation sets

When an asynchronous BPEL process flows, it will invoke an external process, and wait for the external process's call back before continuing. When the workflow engine receives a message, it need to know which instance the message should pass to. In this case, some values within the received message can be used as id for identifying the instance the message should pass to. Such ID is represented by a correlation set. To add a correlation set:

1. Right click on a pool and select Open Correlation Sets Specification... from the popup menu.
2. In the specification dialog box, click Add... at the bottom of dialog box.
3. Give a name to the set and click OK to confirm.
   

   Correlation Sets added