Defining decisions and formulas

Once the schemas are set up the rule builders can begin working with the IDIOM Decision Manager.

• Output nodes in the schemas are identified. Each of these is the site of an “atomic” decision where a result of interest is stored at runtime in the decision request described by the schema. Rule builders assign descriptive names to decisions (such as Set Base Premium), arrange them in processing sequence (an example is given later), and later link them to the formulas that calculate their results.



• Each decision needs at least one formula to calculate its value. Formulas are trees of operations and arguments which operate on input values in the decision request. They are developed in IDIOM using graphical tools and validated and tested using the integrated Test Executive.



• Tested formulas can be output in a logical English form for verification by business experts.

These tasks are typically performed by a domain expert, often with the support of a business analyst. The domain expert specifies the intent of the business rules in any convenient form, which may range from informal (even oral) business language to a formal specification document. The business analyst then uses IDIOM to express the rules in a precise and structured form. With the help of IDIOM’s inbuilt validation and testing facilities, the formula logic is progressively clarified and gaps are identified and closed in consultation with the domain expert. Finally, IDIOM produces the formulas in near-natural language for the domain expert to verify.