Hi, I'm very new to drools and am trying to understand how "facts" are managed by the knowledge session. I've been experimenting with a simple example using drools 5.3.0. I created a simple Account class that has a single "balance" attribute. My rule tests the balance and prints a message if it is less than 100. I am creating a new instance of Account in my main method and inserting it into a stateful knowledge session. I put this into a loop that runs 3 times and never dispose of the session. Each of my Account instances has a balance less that 100. Here is a portion of the code: public static final void main(String[] args) throws InterruptedException { KnowledgeBase knowledgeBase = createKnowledgeBase(); StatefulKnowledgeSession session = knowledgeBase.newStatefulKnowledgeSession(); for (int i = 0; i < 3; i++) { try { Account account = new Account(); switch (i) { case 0: account.setBalance(95); break; case 1: account.setBalance(85); break; case 2: account.setBalance(80); break; default: account.setBalance(80); } session.insert(account); session.fireAllRules(); } catch (Exception e) { System.out.println("Exception: " + e.toString()); } Thread.sleep(1000); } } My rule is: rule "basic rule" when $a : Account (balance < 100) // condition then System.out.println("Account balance " + $a.getBalance() + " is less than 100"); // consequence end What I see is that each time the loop executes only the last instance of Account seems to get triggered. I expected that each time I call "fireAllRules" it would examine all the facts in the session and execute them. So I thought the first time the loop runs I would get 1 activation, the second time the loop runs I get 2 activations, etc. Are all 3 instances of Account still in the working memory or is the latest instance replacing the existing one? Or, once a fact triggers the rules engine, does it not trigger it again? Thanks for any insights, Anne