When an internal auditor discovers an issue such as a programming error allowing multiple accounts for a single address, the auditor should ensure that the corrective actions are both adequate and effective. This includes scheduling a follow-up review (1) to verify that the program has been corrected and that the accounts have been consolidated. Additionally, evaluating the adequacy and effectiveness of the corrective action proposed by management (2) is essential to ensure the issue has been resolved properly. References: = IIA Standard 2500 - Monitoring Progress and IIA Standard 2320 - Analysis and Evaluation.

* Current ratio (A) measures general liquidity (Current Assets ÷ Current Liabilities).
* Quick ratio (C) (Quick Assets ÷ Current Liabilities) excludes inventory and prepaid expenses, giving a more immediate liquidity measure.
* Profit margin (B) measures profitability, and times interest earned (D) measures solvency.
Thus, the best measure of immediate liquidity is the quick ratio (C).

When conducting a review of an electronic data interchange (EDI) application provided by a third-party service, it is essential to determine whether an independent review of the service provider's operation has been conducted and to verify that the service provider's contracts include necessary clauses. These steps ensure that the service provider operates securely and meets the organization's requirements for data protection and service reliability.
IIA References:
* IIA Standard 2100: Nature of Work indicates that internal audit should evaluate the adequacy and effectiveness of controls, including those at third-party service providers. Verifying that an independent review has been conducted and ensuring that contracts contain the necessary clauses are critical steps in assessing these controls.
* The Practice Guide on Third-Party Risk Management advises internal auditors to review the service provider's contractual agreements and independent audit reports to assess the adequacy of controls and compliance with standards.

When creating a risk and control matrix to understand a complex manufacturing process, the internal auditor should start by conducting a walk-through of all related activities. This approach allows the auditor to observe the processes in action, understand the flow of transactions, and identify key controls and risks. A walk- through provides a comprehensive understanding of the operational context, which is essential for developing an accurate and effective risk and control matrix.
The Institute of Internal Auditors (IIA) Practice Guide: Auditing the Control Environment IIA Standard 2210 - Engagement Objectives

External benchmarking using trend analysis involves comparing a company's performance metrics with industry standards or averages over a certain period to identify trends and areas for improvement. Comparing common-size financial statements of the subsidiary with the averages of the industry for the last two periods allows for a normalized comparison by expressing financial statement items as a percentage of a common base figure (e.g., total assets or sales). This method highlights the subsidiary's financial structure and performance trends in relation to industry norms, facilitating a comprehensive analysis. References:
* "Internal Auditing: Assurance & Advisory Services" (The Institute of Internal Auditors)
* "Benchmarking: An Essential Tool for Assessment, Improvement, and Market Leadership" (Michael J.
Spendolini)