Re: [rules-users] problem with drules

I would say, this is one of those cases where it is best to use the right tool for the right job. A programmer can implement this in pure DRL using a few rules, but I don't like the idea, because it will be hard for others to quickly grasp the meaning of the rules. So, I would implement a function (either simple or an accumulate function) to calculate the number of free items and use the rules for what they do best: act on the results. The rule would be like: rule "add free items" where Brand( $name : name, includedInPromotion == true ) Number( $free : intValue > 0 ) from accumulate( $i : Item( brand == $name ), calculateFree( $i ) ) then // add $free items to the order end Take a look at the docs on how to implement the function to calculate the number of free items. It is very simple. This way, your business rule above is clear and easy to understand/maintain. Hope it helps. []s Edson 2009/1/23 niraj manandhar <regniraj(a)gmail.com&gt; -- Edson Tirelli JBoss Drools Core Development JBoss, a division of Red Hat @ www.jboss.com