When determining IT-related risk, understanding the impact on business services supported by IT systems is crucial. Here’s why:

IT and Business Services Integration: IT systems are integral to most business services, providing the backbone for operations, communication, and data management. Any risk to IT systems directly translates to risks to the business services they support.

Assessment of Business Impact: Evaluating the impact on business services involves understanding how IT failures or vulnerabilities could disrupt key operations, affect customer satisfaction, or result in financial losses. This assessment helps in prioritizing risk mitigation efforts towards the most critical business functions.

Framework and Standards: Standards like ISO 27001 emphasize the importance of assessing the impact of IT-related risks on business operations. This helps in developing a comprehensive risk management strategy that aligns IT security measures with business objectives.

Practical Application: For instance, if an IT system supporting customer transactions is at risk, the potential business impact includes loss of revenue, reputational damage, and legal repercussions. Addressing such risks requires prioritizing security and reliability measures for the affected IT systems.

References: The importance of assessing the impact on business services is underscored in guidelines like ISA 315, which emphasize understanding the entity's environment and its risk assessment process​​.