A deviation permit is a controlled authorization to temporarily depart from a specified requirement, process, drawing, material, inspection method, or other approved instruction. In manufacturing, it commonly applies to a defined lot, order, part number, operation, supplier shipment, or time period.
A deviation permit is usually reviewed before the affected work is performed or accepted. It records what requirement is being deviated from, why the deviation is needed, who approved it, the permitted scope, any conditions, and when the permission expires. It may be used for cases such as an approved substitute material, a temporary process parameter change, or an alternate inspection approach.
A deviation permit does not permanently change the baseline requirement. It should not be confused with an engineering change, which updates the approved design or process documentation. It is also related to, but not always the same as, a concession or waiver, which may be used to accept nonconforming output after it has occurred, depending on the organization’s terminology.
In MES, QMS, ERP, or supplier quality workflows, deviation permits are often linked to traceability records, affected units, approvals, and quality evidence so that the temporary exception can be reviewed and contained within its approved limits.