The primary advantage of using internal control questionnaires (ICQs) as part of a preliminary survey for an engagement is their efficiency. ICQs allow auditors to quickly gather a large amount of information about the control environment by asking structured questions that cover key areas of interest. This helps in identifying areas that require further investigation or where controls may need improvement.
IIA References:
* The IIA's Practice Guide on Evaluating Internal Controls mentions that ICQs are useful for obtaining an initial understanding of controls and are particularly efficient when time or resources are limited.
They allow auditors to systematically cover a wide range of control-related topics in a relatively short period.

Physically inspecting a sample of completed processing cycles for defective products provides direct evidence of the effectiveness of the quality control process. This method allows the internal auditor to observe firsthand whether defective products are being identified and removed prior to shipment, ensuring that the process operates as intended. This approach is more reliable than survey results or management reports, which may be subject to bias or inaccuracies.
The Institute of Internal Auditors (IIA) - Standards for the Professional Practice of Internal Auditing, Standard
2320 - Analysis and Evaluation

To test the theory that shutdowns are occurring due to outdated purchasing requirements that have not been updated for changes in production techniques, the auditor should compare the parts needed based on the most current production estimates and the revised materials requirements plan (MRP) with the purchase orders generated from the system. This comparison will help identify discrepancies between what is needed and what is being ordered, highlighting whether the system is failing to update purchasing requirements correctly. This method directly addresses the suspected cause of the shutdowns and provides clear evidence for or against the auditor's theory.
Institute of Internal Auditors (IIA), International Standards for the Professional Practice of Internal Auditing (Standards), Standard 2310 - Identifying Information.

When a manager reviews a staff auditor's workpapers, the primary goal is to ensure the accuracy and completeness of the audit documentation and to provide feedback for professional development. Discussing the workpaper review results with the staff auditor helps identify any areas for improvement and reinforces best practices, making it a valuable learning opportunity. This collaborative approach promotes continuous improvement and skill development within the audit team.
The Institute of Internal Auditors (IIA) - Standards for the Professional Practice of Internal Auditing, Standard
2340 - Engagement Supervision

* A. Determine whether the purchasing department complies with policy by examining a random selection of purchase orders:Correct. Reviewing a random sample of purchase orders is a standard procedure for evaluating compliance with purchasing policies, such as approval requirements, vendor selection, and adherence to budget constraints.
* B. Evaluate whether purchasing requests are properly approved by authorized staff by obtaining independent verification from the vendors:Vendor verification is not typically used to evaluate internal approvals as this information is available within the organization's records.
* C. Ascertain whether material receipts are recorded on a timely basis by reviewing physical inventory stock counts:Physical inventory reviews focus on inventory management and reconciliation, not specifically on the timeliness of receipts.
* D. Determine whether prices charged for goods received are correct by reviewing the appropriate accounts payable record by vendor:While reviewing accounts payable records helps verify the accuracy of pricing, it does not directly evaluate the purchasing department's adherence to procedures.
CIA Exam Syllabus Reference:
Domain V: Performing Internal Audit Services - Audit Engagement Objectives and Procedures.