It is acceptable for an IS auditor to rely on a third-party provider's external audit report on service level management when the scope and methodology meet audit requirements. This means that the external audit report covers the same objectives, criteria, standards and procedures that the IS auditor would use to assess the service level management. This way, the IS auditor can avoid duplication of work and reduce audit costs and efforts. The service provider's certification and accreditation, the report's confirmation of service levels and the report's release date are not sufficient to justify reliance on the external audit report. References: CISA Review Manual (Digital Version) , Chapter 2, Section 2.3.3.

An organization considering the outsourcing of a business application should first conduct a cost-benefit analysis to evaluate the feasibility, viability and desirability of the outsourcing decision. A cost-benefit analysis should compare the costs and benefits of outsourcing versus keeping the application in-house, taking into account factors such as financial, operational, strategic, legal, regulatory, security and quality aspects. A cost-benefit analysis should also identify the risks and opportunities associated with outsourcing, and provide a basis for defining the service level requirements, performing a vulnerability assessment, and issuing a request for proposal (RFP) in the subsequent stages of the outsourcing process. References: Info Technology
& Systems Resources | COBIT, Risk, Governance ... - ISACA, CISA Certification | Certified Information Systems Auditor | ISACA

An IT balanced scorecard is a strategic management tool that aligns IT objectives with business goals and measures the performance of IT processes using key performance indicators (KPIs). It is the most effective means of monitoring governance of enterprise IT, which is the process of ensuring that IT supports the organization's strategy and objectives. Governance of enterprise IT covers aspects such as IT value delivery, IT risk management, IT resource management, and IT performance measurement. An IT balanced scorecard can help monitor these aspects and provide feedback to improve IT governance. References: ISACA Frameworks: Blueprints for Success, CISA Review Manual (Digital Version)

Threat modeling is an approach that enables IS auditors to identify, analyze, and mitigate potential security vulnerabilities within an application by understanding the threats, attacks, vulnerabilities, and countermeasures. This proactive technique helps in designing secure applications.
References
* ISACA CISA Review Manual 27th Edition, Page 276-277 (Threat Modeling)