Overdue Calibration Finder

Overdue calibration: what the auditor asks, and the impact assessment behind it

An overdue instrument is the first thing a certification body auditor samples in a calibration register. The question that follows is harder: was it used to accept product while it was past due, or found out of tolerance at its next calibration, and if so, what was decided about the parts it measured? The standards ask for that judgement to be made and recorded.

The questions, in order

  1. Which instruments are past their due date today? The due date is the last calibration plus the interval; a due date equal to today is due, not overdue (finding 1).
  2. Were any of them used to accept product since the due date? Which lots, from the due date to today (finding 5).
  3. Was any instrument found out of tolerance at its last calibration? What did it measure since the calibration before, and is the impact assessment recorded (finding 4).
  4. Is any lost, quarantined or out-of-service instrument still marked for acceptance? (finding 10).
  5. What falls due before the audit? Book it now (finding 2).

The impact assessment

ISO 9001 and ISO 13485 ask the organization to judge whether earlier results remain valid when equipment proves unfit, and to act on the equipment and on any product affected. IATF 16949 7.1.5.2.1 asks for a risk assessment of an out-of-specification reading, a judgement on earlier measurements, and for the customer to be told if suspect product has shipped. ISO/IEC 17025 7.10 treats it as nonconforming work, including the impact on earlier results.

On Solo, the impact assessment worksheet sets out one block per instrument in question: what the register said, the period with its dates, and blank fields for the lots or parts measured, the action taken, who decided and when. It is your own record; the finder makes no judgement on any product.

IATF 16949 7.1.5.2.1Calibration and verification records

A documented process manages records of calibration and verification. Such records are kept for every gauge and every piece of measuring and test equipment needed to show conformity to internal, legal, regulatory and customer requirements, including equipment owned by employees, by the customer or by suppliers working on site. The activities and records cover: revisions made after engineering changes that affect measurement systems; readings found outside specification when equipment is received for calibration or verification; an assessment of what risk that condition poses to the intended use of the product; when equipment turns out to be faulty or no longer in calibration, a judgement on whether earlier measurements remain valid, with the standard's most recent calibration date and when it is next due; telling the customer if suspect product has been shipped; statements of conformity once calibration or verification is done; confirmation of the software version used for controlling product and process; and records of calibration and maintenance, and of verification of production-related software, for all gauging.

What a certification body auditor asks to see: Calibration records for all gauges including employee-, customer- and supplier-owned; As-received out-of-specification readings with the risk assessment and customer notification; Software version verification records
Where registers usually fall short: Employee-owned gauges outside the calibration system; Out-of-calibration findings with no assessment of previously measured product; Software versions on control equipment never verified
Source: IATF 16949:2016, automotive production quality management
ISO 13485 7.6Control of monitoring and measuring equipment

The organization decides what monitoring and measuring must be done, and what equipment is needed, to give evidence that product conforms, and documents procedures so that monitoring and measuring can be, and actually are, done in a way consistent with the requirements. Where valid results depend on it, measuring equipment is: calibrated or verified, or both, at set intervals or before use, against measurement standards that trace back to national or international standards (if none exist, whatever basis is used for calibration or verification is recorded); adjusted or re-adjusted as needed, with each adjustment recorded; identified so its calibration status can be seen; protected from adjustments that would invalidate the results; and protected from damage and deterioration. Calibration and verification are done according to documented procedures. If equipment turns out not to conform, the organization assesses and records whether earlier measurement results are still valid, and acts on the equipment and on any product affected. Records of calibration and verification are kept. The organization also documents procedures for validating software used in monitoring and measuring, applied before first use and after any change, in proportion to the risk, including the effect on product conformity, and keeps records of the validation results, conclusions and actions.

What a certification body auditor asks to see: Monitoring and measuring equipment register with calibration status and intervals; Calibration procedures and records with traceability to national or international standards; Out-of-tolerance investigation records assessing previous results and affected product; Validation procedure and records for measurement and test software
Where registers usually fall short: Out-of-tolerance findings closed by recalibration with no impact assessment on product measured since the last good calibration; Test software and automated inspection systems never validated; Equipment used before initial calibration
Source: ISO 13485:2016, medical device quality management

See the specimen recall sheetThe calibration register template