A precondition is a logical condition that must be met before a check can be evaluated against the target asset.
In Control Compliance Suite, a check consists of a precondition and the actual check formula. If the check has a precondition, then the precondition is evaluated before the execution of check formula. If the precondition is not met then the check formula is not evaluated and the check outcome is set to Not Applicable.
The common use of a precondition is to verify some condition on the target asset before the assessment of the asset for compliance.
For example, consider the check: Is directory 'XYZ' owned by 'PQR' and has group set to 'ABC'? You may want to first verify if the specified directory 'XYZ' exists on the target computer before checking for the ownership. In this case, the precondition would be a verification of the fact whether the directory 'XYZ' exists.