A decision table is a business rule record, in table format, that consists of conditions, represented in the row and column headings, and actions, represented as the intersection points of the conditional cases in the table. Decision tables are best suited for business rules that have multiple conditions. Adding another condition is done by simply adding another row or column.
Like the if/then rule set, the decision table is driven by the interaction of conditions and actions. The main difference is that in a decision table, the action is decided by more than one condition, and more than one action can be associated with each set of conditions. If the conditions are met, then the corresponding action or actions are performed.
You use templates to modify decision table values in the business rules manager. The templates are designed in WebSphere Integration Developer and contained in the business rule definition. The templates determine which aspects of a decision table you can modify and provide a list of valid values to choose from. You create new rows or columns in the table or new actions based on the templates defined for that decision table, and you modify existing conditions or actions that were created with the template. Decision table templates are not shared between decision tables.
Decision tables support the use of an initialization action rule, which runs before the decision table is executed and allows for pre-processing, such as for creating business objects or setting initial values. You can modify an initialization action rule in the business rules manager, provided that the business rule definition was designed in WebSphere Integration Developer with an initialization action.
Although only one initialization action rule can be created from a single template, the action rule can have multiple action expressions in it, so it can perform multiple actions. If an initialization rule template is defined for a particular decision table, it can only be used in that table.
The otherwise condition is a special condition that will be entered by default if no other condition in the decision table is applicable.
The otherwise condition will only display in the business rules manager if it is included in the decision table definition that was designed in WebSphere Integration Developer. You cannot add or remove it dynamically in the business rules manager.
However, you can templatize actions associated with the otherwise condition. The otherwise condition can be used zero or one time for any condition being checked.
Last updated: Wed 06 Dec 2006 07:08:08
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