Learn in the textbookSignificance, Types, and Structure of Systems Auditing
DefinitionA systems audit (システム監査) is an activity in which independent experts inspect and evaluate whether an organization's information systems are prepared for risks (リスク), that is, whether the mechanisms that keep risks in check (controls (コントロール)) are properly designed and actually working.
ExplanationIts purpose is to evaluate how the organization handles IT-related risks and, through that evaluation, to help the organization achieve its goals. The scope is not limited to systems in operation but covers every stage in the figure above, from planning to maintenance.
AnalogyIt is like an inspector with no stake in a building who reviews it from the design stage through how it is used after completion, and advises the owner to fix anything unsafe.