[rules-users] design question - how to modell this in DRl

Hi, I´m totally new to Drools and DRL. I want / (better words I must, because of my diploma thesis) to connect a couple of different software-applictions using Drools as logical middleware. First i want to translate some kind -like the following ones- of natural rules into DRL and I have no idea how to do this in correct way. Facts are - Order Order contain information about "creationDate" and "customerBelongingTo" - Customer Customer contains information (=days as int value) about "allowedTimePeriodWithoutNewIncomingOrder", on expiry of this time period this customer should me marked to inform a "Person" - Persons There are living persons(maybe) which are interested in "customersWithNoNewIncomingOrder". The should be informed by mail, etc. Please any idea to do this in best DRL way? Thanks Thorsten Trägenap