These directions worked for WebSphere 6.1.0.15. Fundamentally the problem is the lack of JAR files in the default WebSphere CLASSPATH, or the wrong versions. Two things are neccessary to correct this problem:
Adjust WebSphere AS Settings
I'm not certain if these custom websphere application server settings
are required, but since they are present in the working configuration,
I will document them here. The custom settings, and directions on how
to configure them, can be found at: http://docs.jboss.org/seam/2.0.1.GA/reference/en/html/websphere.html
General instructions for setting custom properties are found
at: http://www-01.ibm.com/support/docview.wss?rss=180&uid=swg21284395
Adjust 'Guvnor' Application Specific Settings
In order to ensure we get the 'right' application settings, we configure the application to load from it's own class loader first. Directions to configure this property can be found at https://zuxho14:9045/ibm/help/index.jsp?topic=/com.ibm.ws.console.appmanagement/urun_rapp_classload.html. Select the "Classes loaded with application class loader first" Option.
Modify Guvnor's pom.xml File
The following lines need to be added to Guvnor's pom.xml before rebuilding Guvnor:
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>javax.annotation</groupId>
<artifactId>jsr250-api</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>3.0.0.GA</version>
</dependency>