Validity of audits

The timestamp of the report does not provide information about the temporal validity of audit information. It is likely that the vulnerability did exist before the audit time. As a conservative measure, we consider that vulnerability exists before the current audit report and up to the time of the previous report if it exists, forever otherwise. When a new report becomes available, events generated after the time of the previous report are reevaluated in the light of the current report. They remain as is they were... 

There are very few studies on criterion-based validity of audits. Bailey and Petersen (1989, Polk 1987) describe an attempt to relate safety-program characteristics with accident statistics and monetary losses in a very large study of railroads. They surveyed 18 railroads and scored the them on the following areas of safety programs ... 

In spite of the limitations on both reUability and validity of audits, we believe they are of some use in maintaining an effective safety-management system. Moreover, because they are so entrenched as a tool, we do not expect the use of audits to be discontinued. Therefore, we feel obliged to offer recommendations for how they can be used most effectively. If one plans to use audits, there are several questions that should be asked ... 

There is very little evidence of criterion-related validity of audits. The only substantial evidence we found was a demonstration that maintenance audits correlated with accident rates in a set of 25 manufacturing plants. 

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