Hallo Edson,

thanks for the quick answer. Where can I find  the configuration file where I have to define the ne accumulate function:

drools.accumulate.function.calculateCertainty = org.drools.base.accumulators.NewAccumulateFunction

regards
Thomas


   Or an accumulate function (as long as all you objects implement a commong
interface):

rule "overall certainty"
when
   $cert : Number() from accumulate(
             $f : CertaintyFacts(  ),
             overallCertainty( $f ) )
then
   // do something with $cert
end

   Implement your own formula inside overallCertainty function .

   []s
   Edson