Definition
A documented departure from an approved procedure, plan, requirement or expected result.
Human Explanation
It means that something occurred differently from what was approved or expected.
Why it Matters
Its effect on quality, safety, Data Integrity and compliance must be assessed.
Conceptual Boundary
A Deviation is not automatically critical; significance depends on evidence, impact and risk.
Practical Perspective
Deviations should be recorded promptly, investigated proportionately and linked to CAPA when systemic action is needed.