Q1. Thanks , that makes sense. Q2. I am trying to modify facts, based on events. So in the example given, I am saying if user selects "laptop" then only "DDR" type RAM should be available to choose from, in the RAM category. Thanks abhay ________________________________________ From: rules-users-bounces(a)lists.jboss.org [rules-users-bounces(a)lists.jboss.org] On Behalf Of Wendy Mungovan [w.mungovan(a)yahoo.com] Sent: Friday, May 06, 2011 5:47 PM To: Rules Users List Subject: Re: [rules-users] Basic rules question Abhay, Q1: I think that this will depend on how many different products you have. If there is a small number it is more straight forward to have a rule for each one (so the 2nd option). This allows all you logic to be in one place. If there are a large number of products and writing a rule for each one is intractable you probably would want to look into some generalizations of the rules. Is that helpful? Q2: I'm not quite sure what you are getting at in Q2. Are you trying to write validation rules or rules that are modifying the facts? Wendy ________________________________ From: Abhay B. Chaware <Abhay.Chaware(a)kpitcummins.com&gt; To: &quot;rules-users(a)lists.jboss.org&quot; <rules-users(a)lists.jboss.org&gt; Sent: Fri, May 6, 2011 4:59:46 AM Subject: [rules-users] Basic rules question Hi I am a newbie to rule based applications and trying to get the concept of rules. I have couple of questions about rules to start with, not specifically about Drools though. Q1 - Should rules be data/model specific or can/should they be generic or both ========================================================== e.g. If selected product “TYPE” is “laptop”, then category “RAM” should have all “DDR” type items compatible ( selecting items matching certain property ) OR If selected product is “IBM T42”, then category “RAM” should have “512MB DDR” , “1024MB DDR”, “2048MB DDR” compatible. ( assigning individual items in rules ) OR Combination of both Q2 – How should be the data modeled in above case ========================================================== e.g. in product master, each item ( e.g. T40, T42 ) should have a “TYPE” ( e.g. desktop or laptop ) , all items in category “RAM” should have a “TYPE” ( e.g. DDR ) and then control the assignment of RAM options to the PRODUCT through Rule using “DDR” type ? OR in product master, each item ( e.g. T40, T42 ) should have a “TYPE” ( e.g. desktop or laptop ) , all items in category “RAM” should have a “compatibleProduct” column ( e.g. desktop or laptop ) and control the assignment of RAM to PRODUCT through “dynamic” rules by selecting all the RAMs by passing the “TYPE” of the product to the database handler. Am I making my point clear ? Thanks Abhay This message contains information that may be privileged or confidential and is the property of the KPIT Cummins Infosystems Ltd. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. KPIT Cummins Infosystems Ltd. does not accept any liability for virus infected mails.

Okay .. That brings up another question though, performance / memory wise what's better - to load all the DDR Ram options in memory during initialization and work through memory ? OR pulling them up from database with every call OR pulling them up from database on first call and then putting them into memory and work through memory thereafter? -abhay ================================== From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wendy Mungovan Sent: Friday, May 06, 2011 5:47 PM To: Rules Users List Subject: Re: [rules-users] Basic rules question Q2: So the rule would be something like: rule "RAM type" when $product: Product(type == "laptop"); then //you are looking for the best way to set valid RAM types in the then part of the rule? $product.setRamType("DDR"); //or $product.setValidRamOptions( getValidRamOptions("DDR")); end where getValidRamOptions would be a custom function included through 'import function' so you can then load the choices from some where else. Or if RamOptions were an object in memory you could have a rule like: rule "RAM type" when $product: Product(type == "laptop"); $ramOptions: RAMOptions(type == "DDR"); then $product.setValidRamOptions( $ramOptions.getList()); end Wendy ================================== Regards, Abhay Chaware Sr. Designer | KPIT Cummins Infosystems Ltd | Board: +91 020 6652 5000 | Extn: 2989 | abhay.chaware(a)kpitcummins.com |www.kpitcummins.com P Please consider the environment before printing this e-mail ________________________________ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wendy Mungovan Sent: Friday, May 06, 2011 5:47 PM To: Rules Users List Subject: Re: [rules-users] Basic rules question Abhay, Q1: I think that this will depend on how many different products you have. If there is a small number it is more straight forward to have a rule for each one (so the 2nd option). This allows all you logic to be in one place. If there are a large number of products and writing a rule for each one is intractable you probably would want to look into some generalizations of the rules. Is that helpful? Q2: I'm not quite sure what you are getting at in Q2. Are you trying to write validation rules or rules that are modifying the facts? Wendy ________________________________ From: Abhay B. Chaware <Abhay.Chaware(a)kpitcummins.com&gt; To: &quot;rules-users(a)lists.jboss.org&quot; <rules-users(a)lists.jboss.org&gt; Sent: Fri, May 6, 2011 4:59:46 AM Subject: [rules-users] Basic rules question Hi I am a newbie to rule based applications and trying to get the concept of rules. I have couple of questions about rules to start with, not specifically about Drools though. Q1 - Should rules be data/model specific or can/should they be generic or both ========================================================== e.g. If selected product "TYPE" is "laptop", then category "RAM" should have all "DDR" type items compatible ( selecting items matching certain property ) OR If selected product is "IBM T42", then category "RAM" should have "512MB DDR" , "1024MB DDR", "2048MB DDR" compatible. ( assigning individual items in rules ) OR Combination of both Q2 - How should be the data modeled in above case ========================================================== e.g. in product master, each item ( e.g. T40, T42 ) should have a "TYPE" ( e.g. desktop or laptop ) , all items in category "RAM" should have a "TYPE" ( e.g. DDR ) and then control the assignment of RAM options to the PRODUCT through Rule using "DDR" type ? OR in product master, each item ( e.g. T40, T42 ) should have a "TYPE" ( e.g. desktop or laptop ) , all items in category "RAM" should have a "compatibleProduct" column ( e.g. desktop or laptop ) and control the assignment of RAM to PRODUCT through "dynamic" rules by selecting all the RAMs by passing the "TYPE" of the product to the database handler. Am I making my point clear ? Thanks Abhay This message contains information that may be privileged or confidential and is the property of the KPIT Cummins Infosystems Ltd. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. KPIT Cummins Infosystems Ltd. does not accept any liability for virus infected mails.