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.
References (ISACA): COBIT 2019, BAI03 Managed Solutions Identification and Build; BAI05 Managed Organizational Change.

Capacity management must consider business changes to ensure IT resources can meet future demand. If changes to critical systems are omitted from planning, capacity forecasts will be inaccurate, leading to risks of downtime, bottlenecks, and unplanned outages. A six-month review (A) might be acceptable depending on system dynamics. Lack of administrator input (C) and reliance on service management (D) reduce planning quality but are less critical than missing major business drivers. COBIT DSS01 (Managed Operations) and APO02 (Managed Strategy) emphasize alignment between IT capacity and business requirements.
References (ISACA): COBIT 2019, DSS01 Managed Operations; APO02 Managed Strategy.

The best course of action for an IS auditor who finds that some critical recommendations have not been implemented is to evaluate senior management's acceptance of the risk. The IS auditor should understand the reasons why the recommendations have not been implemented and the implications for the organization's risk exposure. The IS auditor should also verify that senior management has formally acknowledged and accepted the residual risk and has documented the rationale and justification for their decision. The IS auditor should communicate the findings and the risk acceptance to the audit committee and other relevant stakeholders. References:
* CISA Review Manual (Digital Version)
* CISA Questions, Answers & Explanations Database