OBE provides some example workflows which illustrate the various XPDL capabilities and OBE extensions.
Document Approval
A workflow that automates the approval chain for a piece of sales or marketing collateral. It shows a chain of activities performed by humans with the aid of a browser-hosted worklist handler and a WebDAV document repository.
New Employee
A workflow that automates IT provisioning for a new employee by invoking a series of enterprise services.
Enterprise Application Integration
A fully-automated straight-through ('STP') data transformation process. A workflow is triggered by an inbound XML message which it transforms using XSLT then forwards to an external destination.
Travel Bookings
A workflow that automates composite travel bookings. Illustrates compensating transactions for long-running business transactions (sagas).
WfMC Sample Workflow
The WfMC's Sample Workflow Process. This is a sales order processing scenario where customers pay either by credit card or credit account.

Deployment and Execution

The example workflows can either be executed by the basic workflow engine or by the J2EE workflow server. The shell scripts are all in $OBE_HOME/bin and can either be executed from a console window or invoked directly by clicking on them in your OS's native graphical file explorer.

Tip: When working from a console window, cd to the $OBE_HOME/bin directory and establish the OBE client environment for your shell by executing .\obeinit (Windows) or . ./obeinit (Unix/Linux). Having done this you can then change to other directories and execute OBE scripts directly without having to provide qualified paths.

Basic Workflow Engine

J2EE Workflow Server

Manual vs. Triggered Process Instantiation

Most of the example workflows can be either started manually using a worklist handler client or triggered by an asynchronous application event. Typically the <WorkflowProcess> declares at least one <FormalParameter>, meaning that the corresponding process attribute must be assigned a value before a newly created process instance can be started. Event-triggerable workflows initialize this mandatory process attribute from an OUT-mode event parameter.

Execution Tracing

OBE uses Log4J via Apache Commons Logging to log workflow enactment activity. You can enable DEBUG-level logging to see the fine detail of workflow, activity and work item execution, by setting the logging level in log4j.properties thus:
# OBE engine.

# OBE repositories.

# OR simply enable all OBE logging:
Alternatively you can set the logging level via JMX if your application server supports it. JBoss does; you can access the Log4J Service's MBean via the JBoss JMX web console.

Viewing and Editing the Example Workflows

You may wish to open the example workflows in a purpose-written XPDL editor such as Enhydra's JaWE in order to follow the process descriptions more clearly. The JPEG images in this documentation show the activity/transition networks but lack some important details.

Feel free to experiment by editing and redeploying the example workflows. You can either just edit the raw XML in a text editor, or use a generic syntax-directed XML instance editor, or use JaWE. You can edit the workflow in place (i.e., at $OBE_HOME/examples/config/processes) but you might wish to make a backup copy in a different directory before changing anything. The BasicProcessRepository in the basic OBE configuration will detect changed changed process definitions and automatically redeploy them. If you are running the OBE J2EE Server configuration it will be necessary to manually redeploy using the cladmin client (it is not recommended to use the BasicProcessRepository in the J2EE server configuration because the former uses Java file I/O and allocates threads, both of which techniques are expressly forbidden to EJBs by the J2EE specifications).


John Wiley & Sons

The Document Approval and New Employee workflows are reproduced with kind permission from John Wiley & Sons. They were developed by OBE's author Adrian Price as a contribution to the recent publication:

Process-Aware Information Systems - Bridging People and Software Through Process Technology, Marlon Dumas, Wil M. van der Aalst, Arthur H. ter Hofstede, John Wiley & Sons, 2005. ISBN: 0-471-66306-9.

Workflow Management Coalition

The WfMC Sample Workflow is reproduced with kind permission from the Workflow Management Coalition.

Enhydra Community

The workflow diagrams were created with the use of the Open Source Java Workflow Editor - JaWE. Many thanks to the Enhydra team for graciously making a few changes to enable JaWE to support OBE.


Web-based Distributed Authoring and Versioning, an HTTP extension protocol supported by word processors etc. See http://www.ietf.org/rfc/rfc2518.txt
XML Forms language, the W3C's powerful successor to traditional HTML forms. See http://www.w3.org/TR/xforms
Extensible Stylesheet Language, for transforming XML documents. See http://www.w3.org/Style/XSL/
Web Service Description Language. See: http://www.w3c.org/2002/ws/