It seems to me that you should write this as a plain old if/then/else/if... in Java (or any other language). Or is there something else in the way Drools evaluates rules over facts in working memory that makes it highly desirable to use rules? This has been asked before, and more often than not there was a way to avoid a way of establishing the sequence of RHS execution by salience or whatever. So, if you do need rules, you can assign decreasing salience values to all your rules. To terminate, either call the engine's halt() method, or retract the fact(s) triggering the rules. But note that all conditions will be evaluated before the first RHS is executed. To aoid this: see the 1st sentence. -W On 26 September 2011 06:54, Saurabh Pandey <meet.saurabhpandey(a)gmail.com&gt;wrote:

This isn't an if statement evaluated left to right with an && between each part. Drools uses the rete algorithm to make execution more efficient. Put very simply (and probably inaccurately) Rete creates an evaluation tree where inputs are put in the top and activations come out the end. In this case the tree would have: One node that evaluated condition1, this node outputs a list of all the facts that matches it. A node for condition 2 which outputs a list all the facts that match that condition. A node for the rule, this takes the outputs of the other two nodes and produces an activation for each pair of items (assuming condition 1 and 2 aren't related). If you had another rule with condition1 and condition3 then they would both share the first node greatly improving efficiency and re-evaluation time. Thomas ************************************************************************************** This message is confidential and intended only for the addressee. If you have received this message in error, please immediately notify the postmaster(a)nds.com and delete it from your system as well as any copies. The content of e-mails as well as traffic data may be monitored by NDS for employment and security purposes. To protect the environment please do not print this e-mail unless necessary. NDS Limited. Registered Office: One London Road, Staines, Middlesex, TW18 4EX, United Kingdom. A company registered in England and Wales. Registered no. 3080780. VAT no. GB 603 8808 40-00 **************************************************************************************