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Decide on Rule Sets, Rule Hierarchies, and Sequence of Execution within a Rule Set

This is usually accomplished by decomposing your use case or business event or event response process into tasks. If you followed the approach in this book, you already did this during process analysis. You may need to decompose tasks further and to meet with screen/Web designers. In this step, for a simple business event, you group rules together for one task or subtask. In this way, your application can call on the rules service to perform rule execution for that task or subtask.

For very complicated business events, with many sets of rules, you may have the option within your product of creating rule hierarchies. Rule hierarchies are another mechanism for determining the sequence of rule execution. Refer to your specific product documentation on how best to group rules for proper execution sequence.

Within a rule set, sometimes you can determine the execution sequence of rules. Often the default is the order in which you enter the rules. Usually, you can override this.

Step 12.8.4: Define the Object Model to the Product

Most often, you can import your object model from an object modeling tool into the rules tool.

Step 12.8.5: Determine How to Express the Rules

You need to become familiar with your product's rule language or alternate forms for entering rules. You may be able to investigate two alternatives. You will enter some rules using the native rule language of the product. To assist guardians in changing the rules pertaining to their members, you will create a rule interface through which the guardians can enter their own rules. The interface will limit the kinds of rules the guardians can enter to rules about homework, chores, and so on. It will provide a mechanism for entering rules that does not require technical expertise.

Step 12.8.6: Enter Rules into the Product

The rules are entered into the rules product either directly using the rule language syntax or through graphical or a wizard capability. Again, if you have a rules repository separate from the rules product, you will want to ensure that the rules reside in the rules repository.

Note ILOG features a Business Rule Language (BRL). Business users

can construct rules in a natural language like syntax, customizable — because no single BRL can fit all — to the terms and vocabulary of any business domain. If rules are to be defined as constraint, inference, action, and so on, then these classifications should be made in the BRL, where business users will benefit. Rules can be created in any editor or using the ILOG Rule Builder environment, and loaded into the engine as a file, stream, URL, in XML, or created on the fly from within application code using the ILOG Rule Factory API. An application may also remotely attach to the ILOG Rule Builder, allowing users to edit, debug, and execute rules, while the application maintains control of the rule engine. A point and click editor allows business users to create rules in a natural language syntax called the Business Rule Language. The editor is also available as a JavaBean or Web component, enabling it to be built directly into any application, allowing rule editing directly from within the application or Web browser.

Note For HNC Software's product, the business rules are written in the

Advisor Structured Rule Language (SRL). While SRL is a programming language, the grammar is English-like, making it easy to read for nonprogrammers, and fairly simple to learn. The Brokat Advisor Builder IDE provides a range of graphical tools to assist you in developing your business rules.

12.8.7: Determine if Some of the Rules Need to Be Coded in Procedural Nonrule Code

As above, this will depend on the full functionality of your rule language within your product.

12.8.8: Test the Rules

Again, this is the fun part.

Case Study: 12.8 — Design for Rules in a Commercially Available Service-Oriented Rules Product

Case Study Instructions:

- Design for the rules in the service-oriented rules product. Do so for rules

about answers to the member questions and for invoicing rules. Case Study Solution: A solution for HNC Software's product is in the next chapter .