How to Qualify a Calibration Provider for GMP Activities

Qualifying a calibration provider should produce a defined approved scope: which instruments, quantities, ranges and locations it can cover, with what performance and conditions. A “qualified supplier” checkbox without these details does not support an informed decision about the next assignment.

Relevant accreditation is important evidence of competence; the customer must still establish whether it fits the requested service and control the outsourced activity. The following approach connects selection, agreement and monitoring without replacing review of each calibration certificate.

1. Describe the service before comparing quotations

For each instrument family, specify the quantity, actual operating range, required points, configuration and accessories. Depending on the application, a chain includes the probe, cable, transmitter, indicator and acquisition system: calibrating one component does not automatically cover the whole chain. Identify what must remain installed and what can be transported.

Communicate metrological requirements and operating conditions, the uncertainty required from the service, the need for initial and final results, and any conformity statement and decision rule. Clarify access, safety, decontamination and plant availability. The provider needs to identify an unachievable requirement before the order, rather than after delivering an unusable certificate.

2. Check competence and accredited scope

Use the accreditation body's database to verify the laboratory's identity, current status, scope and possible suspensions or restrictions. Keep dated evidence of the check. A logo on a commercial website and an old accreditation certificate do not necessarily describe the current situation.

Read quantity, instruments, range, method, conditions, calibration and measurement capability (CMC) and location together. Coverage at the provider's laboratory does not extend by analogy to the customer's site. Activities outside the scope must be identifiable and assessed separately, without being presented as accredited.

For the meaning of accreditation, see ISO/IEC 17025 and GMP activities. Here, the decision is whether the available evidence supports the specific assignment.

3. Assess achievable performance on your instrument

The CMC is not a promise that every instrument will receive that same uncertainty. Device resolution, repeatability, stability and condition can increase the actual uncertainty. Request a technical assessment based on the model, configuration, previous results and site conditions; distinguish this forecast from the value reported after measurements.

Check that the method covers the required performance: electrical simulation does not necessarily measure probe behaviour; a static comparison does not establish dynamic response. Traceability evidence must match the quantity and method. A collection of the provider's reference-standard certificates alone does not demonstrate correct execution or an adequate uncertainty budget.

4. Agree on activities, data and responsibilities

For outsourced GMP activities, define a written agreement with clear responsibilities and communications. State who authorizes adjustment or repair, when to acquire as-found results, how to document intervention and which as-left measurements are needed. A general maintenance authorization can remove initial evidence needed for an investigation.

Agree on the results, units, uncertainties, identification and conditions to be delivered, any decision rule, anomaly notification times, access to relevant records and revision handling. Define prior assessment and approval of subcontracting arrangements under applicable requirements; a change of laboratory must not go unnoticed.

The customer retains responsibility for reviewing results and authorizing instrument use. The agreement must permit audits of outsourced activities; the depth, method and review of qualification should be justified by risk and evidence, without inventing an identical visit frequency for every provider.

5. Original matrix for a traceable decision

Complete each row with the decision owner, retained evidence, action deadline and remaining limitations. A high average score does not compensate for an essential unmet requirement. Outcomes include approval for a defined scope, conditional approval after gaps are closed, or non-approval of the requested service.

6. Simulated case: accredited in the laboratory, requested on site

A GMP laboratory requests calibration of an installed temperature measurement chain from 20 to 80 °C. The candidate presents an accredited scope for the same quantity and range, but the relevant entry applies only to its permanent laboratory. The quotation promises work at the customer's site without explaining this discrepancy.

The customer neither concludes that the provider is incompetent nor automatically approves the service as accredited. It requests documented clarification of location, method and expected uncertainty. Options include a genuinely covered service, a technically permissible transfer with reinstallation checks, or another qualified solution. Any non-accredited activity requires explicit assessment of acceptability and competence against applicable requirements.

After approval, check the first result and monitor compliance with the order, anomalies, revisions and scope changes. An isolated delay and an identification error do not automatically carry the same weight. An expanded instrument inventory or a new location requires review of the approved scope: previous qualification is not unlimited authorization.

Connect the agreement to as-found/as-left results and return to the Calibration and Metrology hub.

7. Sources and application limits

Checked on 1 October 2026. The matrix and case are original; they neither assess real providers nor prescribe a universal audit programme.

1. EU GMP, Chapter 7: revision 1, effective 31 January 2013, full text; responsibilities for outsourced activities. Application here concerns medicinal products for human use.
2. Accredia, accreditation tables: 23 September 2022; sections on scope, locations and CMC consulted. Training material, not a provider's current scope.
3. Accredia, certificate Q&A: 27 September 2023; answers on achievable uncertainty and qualification consulted.
4. ENAC, PAC revision 7: April 2024; scope annex consulted, distinguishing laboratory and on-site activities.
5. ISO/IEC 17025:2017: official catalogue, confirmed in 2023; full text not consulted. Use a controlled copy for detailed requirements.