During an ISO/IEC 27001 audit, auditors must obtain absolute assurance that every single process is effective and conforms to the standard requirements.

The correct understanding centers on the nature and purpose of an audit in the context of ISO/IEC 27001. Absolute assurance that every single process is effective and conforms to standard requirements is fundamentally unachievable in an auditing scenario. Auditors strive to gather sufficient evidence to form an opinion about the effectiveness of the information security management system (ISMS) and its compliance with ISO/IEC 27001, but complete assurance cannot be guaranteed for several reasons.

Firstly, audits typically involve sampling processes and reviewing specific areas, which means that it's impractical to assess every single process in detail. This approach acknowledges inherent limitations, such as time constraints and the complex nature of organizations, where many processes may interact and influence one another.

Moreover, the standard particularly outlines that the goal of an audit is to identify nonconformities and areas for improvement rather than achieve scrutinized perfection across every aspect of an organization’s practices. Auditors use their judgment and technical expertise to evaluate the ISMS, leading to conclusions based on evidence rather than an absolute measurement of every single element.

While achieving a high degree of confidence in the results is a priority, auditors work with reasonable assurance—recognizing that varying degrees of risk and organization complexities make total assurance unrealistic. This understanding