Yes, there are. I work (as external consultant) for a few of those, which I am not allowed to disclose here... But: A decision pro/con Drools should be based upon YOUR specific criteria, not those of other enterprises, right?! In my experience, Drools is both stable and performant enough to be used in productive environment. We tested several deployment and architecture variants (esp. for batch processing), with <100 Rules and <10 facts for each data-row within our batches, but a few million rows. Worked out fine. We currently use 3.0.6, no major issues. regards, Gernot -- Dr. Gernot Starke Willi-Lauf Allee 43, D-50858 Köln Tel. +49 (0) 177 - 728 2570 Mail: gs(a)gernotstarke.de http://www.gernotstarke.de http://www.arc42.de

We deployed a Drools based solution to a client in the pharmaceutical distribution world (Fortune 100 company :-). We used Drools to power the decisions an interactive voice ordering system. A small number of rules initially but growing constantly based on user metrics. System has been running for a couple of years now. On 7/18/07, Geoffrey Wiseman <geoffrey.wiseman(a)gmail.com&gt; wrote:

Hi, We are using Drools VERY succesfuly around 3 years (We started with version 2.x). And it has being so usefull that now we have a very big system running on more than one customer in telecom market. Main (Obvious) Advantages: 1-All open source and community envolvment benefits (Well tested code, new and innovative use cases, new features added quickly, source code available........and ....many more) 2-Very simple, quick, cheap and clean implementation of new features. 3-No need to re-build entire system due to new or changes in business rules/needs, VERY high degree of flexibility and freedom 4-Knowledge is "almost explicit" and start to become formal for the organization 5-You can build framworks that accepts different Object Models and Rules, while all the infra-structure supporting it is the same, so with basically same code we can build different solutions. This leads to rocket-time implementations and extremally short learning curves. What we use Drools for? 1-As a rules engine as usual 2-For reporting stuff (Good for generating reports with different views of data, very easy to reformat dates, numbers and so on...) 3-For discimination networks (We are affraid of shadow facts on this :) ) Currently we do have a server running around 300 rules, where we assert millions of facts at once. The objective is to guide and rate telecom usage events. We are able to apply those 300 rules over 20 Milion facts and get results (Guided and Rated) around 1 hour(Note: First we have to read many binary files, perform a charset conversion on data, load it in our object model, assert objects in working memory, apply around 200 rules to enrich the data, assert again in a new working memory, and rate the events accessing external RDBMS databases - caching results of course). Acctually what we do is to in batch/server workflow assert those facts twice (Two working memories) in sequence. The first one is to "enrich" the data (Discrimination Network...) and instead of modifying the events here, we just go to next step and then assert those facts again and apply rating rules. It seams to perform better. Issues and Cares: 1-Avoid at ANY cost cartesian products. It kills you. This is a common mistake, easy to do, easy to detect (Symptons are typical...Slow down performance, memory consuption is very high, application will probably swap), hard to find where it is and easy to solve. 2-Memory consumption is always an issue 3-Have a very good design to access external databases (If possible, think about on having a database cache running outside your JVM) 4-Follows Edson Tirelli's tips and tricks. 5-Be carefull with numbers and dates formatting, conversion and calculation (as in my experience Java performs poorly on this area) -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Anstis, Michael (M.) Sent: quarta-feira, 18 de julho de 2007 11:10 To: Rules Users List Subject: RE: [rules-users] Entreprise using Drools with success We short-listed Drools against ILOG and Fair Issac. V4.0 was to be the technical winner but for (a) per CPU support cost and (b) internal politics. It was (and still is) a shame we had to "sell out" :-( Mike -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Brian Sam-Bodden Sent: 18 July 2007 15:01 To: Rules Users List Subject: Re: [rules-users] Entreprise using Drools with success We deployed a Drools based solution to a client in the pharmaceutical distribution world (Fortune 100 company :-). We used Drools to power the decisions an interactive voice ordering system. A small number of rules initially but growing constantly based on user metrics. System has been running for a couple of years now. On 7/18/07, Geoffrey Wiseman <geoffrey.wiseman(a)gmail.com&gt; wrote: before, everything I've does Drools / choice for _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users