Section 7.5.6 of ISO 13485 covers production and service provision processes whose outputs cannot be verified by subsequent monitoring or measurement. For these processes, deficiencies become apparent only once the product is in use. ISO 13485 does not use the term “special process”: it is sector usage, but it describes exactly this case. When after-the-fact verification is impossible or insufficient, upstream validation becomes mandatory.
Why this specific regime exists
For a product that can be checked by inspection, a measurable mechanical part for example, conformity is verified on each unit produced. For a special process, this verification would mean destroying the product, or the defect would remain invisible until the patient is exposed. Sterilisation is the most direct illustration: inspecting each sterilised unit would render it unusable.
Validation demonstrates, once and for all before production starts, that the process reproducibly achieves the required results when conducted within defined parameters. It comes with revalidation criteria, triggered by a change to the process, the equipment, the product, or after an observed drift. This revalidation clause is the one internal teams most often forget.
Common special processes in the medical device sector
Sterilisation. Performed in-house or outsourced, sterilisation is the special process par excellence. The applicable standards are ISO 11135 (ethylene oxide), ISO 11137 (irradiation) and ISO 17665 (moist heat). Validation is structured into three qualifications: installation (IQ), operational (OQ) and performance (PQ). Outsourced sterilisation remains the manufacturer’s responsibility and falls under documented supplier control as part of purchasing (section 7.4). Subcontracting the process does not subcontract the responsibility.
Sterile barrier sealing. Sealing the packaging that maintains the sterile state is a special process in its own right, often treated as a mere machine setting. Its temperature, pressure and time parameters must be validated in accordance with ISO 11607-2.
Welding and bonding. Laser welding, ultrasonic welding, structural bonding. The critical parameters of power, speed, pressure and time must be identified, their range validated, and their monitoring in production ensured.
Injection moulding. For plastic components whose dimensional or material conformity cannot be verified exhaustively during production.
Is embedded software a special process? No
This is the most frequent confusion. Software that is part of the device, or that is the device, is not a production process. It falls under design and development (section 7.3) and its life cycle under IEC 62304, with a level of rigour proportionate to the software safety class A, B or C. Its control is achieved through software verification and validation within the design controls, not through a process IQ/OQ/PQ.
What section 7.5.6 actually targets on the software side is software used in production and service provision: an automated test bench, a controller driving sterilisation equipment, a production tracking system. These applications must be validated before their first use, following a risk-proportionate approach. Confusing the two leads to documenting the wrong object and leaving a gap in the file.
The minimum content of a process validation
Validation protocol. Defines the process, the critical parameters, the acceptance criteria, the equipment and the number of trials required.
IQ (Installation Qualification). Verifies that the equipment is installed in accordance with the supplier’s specifications and internal requirements.
OQ (Operational Qualification). Demonstrates that the equipment operates repeatably within the defined limits.
PQ (Performance Qualification). Demonstrates that the process reproducibly produces a product conforming to specifications, under actual production conditions.
Validation report. Summary of the results, conclusion on the validation, definition of the validated process parameters and the intervention limits.
These three qualifications are not the validation on their own. It is their documented sequence, completed by the protocol and the report, that constitutes the validation defensible in audit.
A process validated on paper but without revalidation criteria or monitoring of the parameters in production does not hold up in a certification review. It is a demonstration exercise, not a documentary filing task.