Defining clear, comprehensive, and testable requirements is critical before selecting and implementing a software product. Without well-documented requirements, the risk of choosing a solution that does not align with business needs increases significantly. A support contract (C) is important for long-term use, and escrow (D) may protect against vendor insolvency, but neither ensures that the product fits the organization's objectives. A post-implementation review (B) only evaluates success after implementation, which may be too late to correct fundamental misalignment. ISACA's COBIT framework (BAI03 and BAI05) stresses the importance of requirements gathering as the foundation for effective solution acquisition and development.

Default accounts and passwords are a common security vulnerability in cloud-based applications.
Ensuring that these are disabled or changed immediately upon implementation helps protect the system from unauthorized access and security breaches. This should be a priority to safeguard the application and data.
While verifying maintenance agreements, preventing source code alterations, and addressing old program versions are important steps, securing the system by disabling default accounts and passwords is the most critical first action to prevent immediate threats.

Performing a walk-through of job functions allows the IS auditor to directly observe how tasks are executed in practice, confirming whether separation of duties is effectively implemented. This provides more reliable evidence than documentation or organizational charts, which may not reflect actual operations.