To evaluate a preventive computer maintenance program effectively, what should an IS auditor consider most helpful?

In evaluating a preventive computer maintenance program, the most helpful aspect for an IS auditor is a written preventive maintenance schedule. This schedule is essential because it outlines specific tasks, timelines, and responsibilities assigned to keep the system functioning optimally. A detailed schedule provides a clear framework for accountability and helps ensure that maintenance activities are performed consistently and in a timely manner.

While a system downtime log may provide insight into past incidents and operational impacts, it does not proactively influence future maintenance efforts. Similarly, vendors' reliability figures might inform the choice of hardware or service providers but do not directly relate to the effectiveness of the preventive maintenance program. A regularly scheduled maintenance log can offer evidence of performed maintenance activities, but without a comprehensive schedule, it lacks the proactive nature that the written preventive maintenance schedule entails.

Thus, the written preventive maintenance schedule is crucial as it not only sets expectations but also fosters a culture of regular upkeep and minimizes the likelihood of unexpected system failures.