Editor's Note:
This review has been updated to incorporate our own Waltz DB 16 benchmark test results for ILOG JRules 6.0. In the original version of the review, we reported a Waltz DB 16 result provided by ILOG. At the time, we believed this number accurately reflected JRules' performance. However, after the review published, ILOG asserted that the performance number we reported was based on a first-generation Rete algorithm and not the current algorithm which the product now uses. Indeed, the new Waltz DB 16 results for JRules 6.0 (we tested both standard and optimized modes) are much better than the 88-second time we originally reported, though they still lag behind the time for Blaze Advisor 6.1.

We’re all familiar with the conventional relationship between the business department and IT: The business department needs a new application or they need to change an existing application. They approach IT and ask how long it will take and how much it will cost. If within budget, IT gathers what it calls requirements and, after approval of the requirements, begins coding. Then come the testing, changes, finger-pointing, backroom dealing, and more finger-pointing. In technical terms, IT has responsibility for both the validation of the application (Did we build the right system?) and the verification requirements (Did we build it properly?).

A BRMS (business rule management system) isolates the pure business logic of a project from the control logic and presentation code, and puts it into a rule base space. Effectively, a BRMS moves verification back to the business department where it belongs. Using a BRMS, the business user, not the IT department, writes the rules, change the rules, and delete the rules. The IT department is responsible for the construction of the system so that it is fast, scalable, and easily maintainable.

Fair Isaac’s Blaze Advisor and ILOG’s JRules are the longtime leaders in enterprise BRMS. JRules has always played catch-up to Blaze Advisor on rule building and management, but has led Blaze in speed. Now, as each reach version 6, JRules has some advantages in rule management and Blaze Advisor has turned on the after-burners, surpassing JRules in performance. I have finally compared these two solutions head-to-head, ringing all the bells and blowing all the whistles. I also ran the Waltz DB 16 benchmark on both rule engines for speed comparisons.

In interpreting benchmark results, remember one thing: They are general in nature and stress the engine in ways that your company may or may not need to, especially if the rules in your application are not especially interactive. (Read a more in-depth discussion of the classic rule benchmarks, or read a broader examination of the rule management space at BRMS.)

What does a BRMS do for the bottom line? Last November at the annual Business Rules Forum I heard customer after customer regale audiences with how they had saved incredible amounts of time and money by using a BRMS. How much? Some reduced the time required to make changes from months to days or hours or minutes. Some now make changes within minutes, test within an hour or two, and put them into production the same day.

Fair Isaac Blaze Advisor 6.1
Blaze Advisor 6.0 and 6.1 are virtually the same except for one thing: speed. Unlike previous versions, Blaze Advisor 6.1 uses the Rete III algorithm that Fair Isaac obtained when it purchased RulesPower Technology last year. The speed increase, compared to previous incarnations of Blaze Advisor, is phenomenal. For example, Blaze 6.1 completed the Waltz DB 16 benchmark on my Windows XP machine (2.0GHz and 1MB of RAM) in 3.5 seconds, putting Blaze ahead of JRules (38.9 seconds standard, 10.2 seconds optimized) but still a few steps behind OPSJ from Production Systems Technologies (1.6 seconds), still the fastest rule-based system on the planet Earth.

Blaze Advisor uses a form of backward chaining that uses a “when needed” flag on a rule as well as a “when changed” flag on attributes, helping to speed the processing of certain common problems such as configurations and resource management. In addition, Fair Isaac has built in score models for insurance applications, loan applications, and other financial problems. The rules can use either developer-centric dot notation or they can use regular English (or French or whatever language). As in JRules, however, these regular expressions must be added by the programmer during the development process. Blaze Advisor has always been one of the friendliest of the BRMS tools to business users, providing pleasant graphical development environments and understandable rule flow charts, decision tables, rule trees, and object models.