What aspect should an IS auditor prioritize when planning an audit of IT controls?

An IS auditor should prioritize understanding relevant business objectives when planning an audit of IT controls because this knowledge enables the auditor to align the audit with the organization's strategic goals. By comprehending the business context, the auditor can identify which IT controls are most critical to ensuring the integrity, confidentiality, and availability of information systems that support those objectives.

This approach allows the auditor to focus on areas that have the highest impact on the organization’s performance and risk exposure. It also provides insight into the controls that need more stringent testing and helps to identify any gaps or weaknesses that could affect the achievement of business goals. Thus, aligning the audit with business objectives enhances the relevance and value of the audit process, ensuring that it provides actionable recommendations that aid the organization in achieving its objectives.

The other aspects, such as setting a strict timeline for report completion, identifying past audit issues, and improving the technical skills of the audit team, while important, do not directly contribute as significantly to the relevance and effectiveness of the audit as the understanding of business objectives. Prioritizing these elements could lead to a misalignment of findings and focus, potentially leaving critical areas unaddressed.