You use the Comparison Rules application in the Reconciliation module to create new comparison rules; view, modify, or duplicate existing comparison rules; and delete comparison rules.
A comparison rule is an optional component of a reconciliation task. It defines how to compare objects or attributes of a child or parent object in one data set with a child or parent object in another data set when the system executes a reconciliation task. For example, you can set up a comparison rule to compare processors on computers in IT assets with processors on computers in deployed assets. A task can include more than one comparison rule.
To create a comparison rule, you must define Data Set 1 and Data Set 2. Then you specify either a matches found definition or an attributes equality definition, but not both. You can also define a filter for Data Set 1 or Data Set 2 to limit your comparison to a subset of either data set. A matches found clause requires at least one data set filter.
If you use the IBM® Tivoli® Change and Configuration Management Database, you can also define full configuration item (CI) comparison rules that let you compare CI relationships. Full CI comparison rules compare the relationships of authorized CIs and the attributes associated with the authorized CIs with the relationships and attributes associated with the corresponding actual CIs.
After you create a comparison rule, you use the Reconciliation Tasks application to associate the rule with a specific reconciliation task, and the system includes the comparison rule each time it executes the reconciliation task. When the system runs a reconciliation task, it processes link rules first. A link rule establishes the basis of a reconciliation by identifying an attribute of a partition or top-level object in one data set to match with a specific attribute of a partition or top-level asset in another data set. A top-level object is an object that has no higher level parent object. After the system successfully links an object in Data Set 1 with an object in Data Set 2, it processes any comparison rules in the reconciliation task.
For example, you can define a link rule that uses serial numbers to match notebooks in authorized assets with notebooks in deployed assets. For the same task, you can define a comparison rule that evaluates whether the amount of RAM on the notebook in authorized assets matches the RAM on the notebook in deployed assets. If the system successfully matches a notebook in authorized assets with a notebook in deployed assets, it processes the comparison rule to determine whether the amount of RAM in the authorized asset record matches the amount of RAM in the deployed asset record.
When the system executes a reconciliation task, it lists results of comparison rule evaluations in the Asset Reconciliation Results application.