2 parts of the puzzle are already figured out:

1) Configuration delegates to a subclass internally. So

new Configuration("spring")

creates and delegates to a SpringConfiguration, which can build a specialized SpringProcessEngine

2) Maven properties are passed as system properties. So

public class PropertyTest extends TestCase {

 public void testProperty() {
 System.out.println(System.getProperty("jbpm.cfg.type"));
 }

}

can be run like this

C:\wsjbpm4\jbpm4\modules\test-pojo>mvn -Dtest=PropertyTest -Djbpm.cfg.type=spring clean test

...

Running org.jbpm.test.activities.PropertyTest
spring
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.047 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
...

what else do we need ?