Static Analysis of Rule Testing
A Decision Table displays multiple related rules in a single spreadsheet-style view. In Rules Designer a Decision Table presents a collection of related business rules with condition rows, rules, and actions presented in a tabular form that is easy to understand. Business users can compare cells and their values at a glance and can use Decision Table rule analysis features by clicking icons and selecting values in Rules Designer to help identify and correct conflicting or missing cases.
Overlap checks
You can set Decision Center to check that the values you enter in your decision tables or decision trees do not overlap or are not identical.
For example, in the following condition statements, customers who are 29 years old satisfy the condition for both rules:
- Age is between 17 and 30
- Age is between 29 and 40
If these two conditions stem from the same condition node of a decision tree, or are part of the same column or within a partitioned group of cells in a decision table, Decision Center signals it as an overlap error.
Gap checks
You can set Decision Center to check that the values you enter in your decision tables or decision trees consider all possible cases. This ensures that there are no gaps in your conditions.
For example, in the following condition statements, customers who are 31 years old are never taken into account:
- Age is between 17 and 30
- Age is between 32 and 40
Decision Center reports a gap error.
In decision tables, Decision Center evaluates gaps for all the entries in a given column, or within partitioned groups of cells. In decision trees, Decision Center evaluates them for the branches of a condition node or for the entire tree.
Symmetry checks
You can set Decision Center to check that all partitions of a decision table use the same set of items. You can verify symmetry for the whole table or for specified columns. Such analysis is useful to enforce that you have covered all choices in a decision table.
By default, symmetry analysis is off, allowing you to create nonsymmetrical tables.
To help understand Decision Table concepts, consider a set of IF/THEN rules that determine if a driver is eligible for a license, and an equivalent Decision Table. Note if a driver has taken a driver training class then the driver has training certification.
Decision table and decision tree checks
In addition to the basic syntax checks, you can perform overlap and gap checks on decision tables and decision trees. You can also perform symmetry checks on decision tables.
