Its actually resend from dev list as I was pointed out that topic is rather about drools usage not new feature development. Thats very promising ... I am looking for some lightweight solution of fact sets separation withing single working memory. ... I am possibly messing up with terminology therefore please let me present an example. I have set of facts "Set 1" contains: - Fact ( name==A, property==1) - Fact ( name==B, property==2) "Set 2" contains: - Fact ( name==A, property==1) - Fact ( name==C, property==2) - I would like to execute my dedicated package of rules for instance of "Set 1" within single working memory. - When "Set 1" is inserted ( instantiated ) twice or more into the working memory I would like to separate the scope of rules to this particular instance - I would like to insert "Set 2" at the same time multiple times and execute separate set of rules dedicated for "Set 2" separately on each of inserted instance of "Set 2" - In some cases I would like to have access to facts from other instances of different sets within same working memory. eg.: - rule associated to "Set 1" checks all the occurrences of Fact( name == A ) - means it could read state of Fact from other instances of "Set 1" and "Set 2" - rule associated to "Set 1" checks state of fact associated to Fact ( name == A ) from "Set 2" I could do it currently by - adding extra fact indicating instance to working memory - adding property to my Fact indicating origin ( instance in this case ) - altering each rule. Example: reaching facts in particular instance ... when: Instance ( instanceId: id, name == "Set 1") Fact ( ... , origin == instanceId ) ... then ( ... ) Example: reaching fact in multiple instances ... when: Fact (...) ... then Idea behind is very prosaic. Majority of the rules are written in my case with single instance context in mind. Only sometimes there is a need to look out of the "hedge". So my example requires more typing and better specification for *modeler* ( name of the role in my org - means person who writes the rules ) who is using simpler single *model* ( set of rules + set of facts ). I am trying to implement this using multiple, chained working memories but maintenance of graph of working memories does not look very practical for longer term and its not working perfectly. How could it be implemented - high level of course Or better ... How I would like to use it :) RuleBase ruleBase = RuleBaseFactory.newRuleBase(); ruleBase.addPackage ( "Set1" , MyPackageForSet1 ); // 1st argument is context name, 2nd compiled rule package WorkingMemory wm = ruleBase.newStatefulSession(); wm.insertInContext ( "Set1", new Fact (A,1) ) // this could be also solved by implementing interface on the fact // inserting instance and context pointer after fact creation // and then inserting it to wm regular way. than if there would be a need to reach fact from other contexts I would specify it using something-like-this syntax ... when Fact ( ... ) // facts within same context and instance *.Fact ( ... ) // facts from all facts sets (contexts) <ContextName>.Fact ( ... ) // facts from all // instances of specific context. <ContextName>(*).Fact ( ...) // same as above <ContextName>(1).Fact ( ...) // facts from specific // instance of specific context. Ok. What I am looking here. - is something like this possible now out of the box and I skipped this nice chapter in documentation? - does it make sense from your point of view to implement this kind of functionality. In my case it has lets say business justification and will allow to implement really complex solutions in nice way. - Does this problem have some buzzwordish/scientifically blessed name so I can express it better next time or maybe find something interesting in mailing list archive. (Changing subject to something more sufficient is more the welcomed ) - is it at all possible ;) - what I am missing in this problem description? And big thanks for reading it till the end. tk.