The level of assurance required for an assessment can vary depending on the purpose, scope, and objectives of the assessment. It is crucial to define the desired level of assurance (low, medium, or high) before beginning the assessment to ensure that the approach, methodology, and resources allocated are appropriate. This helps in setting clear expectations and aligning the assessment process with the organization's risk tolerance and regulatory requirements.References:

ISO 19011:2018 - Guidelines for auditing management systems

COSO Enterprise Risk Management – Integrating with Strategy and Performance