If the decision was more complex than could easily be handled with an expression or JavaScript, you could have used a Java class to implement the decision logic. To do that, you would have used a handler tag to point to a Java class that implements the DecisionHandler interface:
<decision name="CapEx Decision">
<handler class="com.someco.bpm.CapExDecisionHandler" />
<transition name="transBoard" to="Board Review"></transition>
<transition name="transMgt" to="Management Review"></transition>
</decision>
