A Guide to Performance Qualification under AS/NZS 5369:2023

Validation involves establishing documented evidence that a process can consistently achieve its specified outcome. Within this framework, equipment testing and PQ perform different functions.

Equipment qualification establishes that the equipment is installed and operating in accordance with its specified requirements.

Performance Qualification then applies that equipment to the actual reprocessing process and assesses its performance using the loads and reusable medical devices it is intended to process.

The distinction is important.

A washer-disinfector may achieve its programmed time and temperature parameters, yet this alone does not demonstrate that a particular reusable medical device has been effectively cleaned.

Similarly, a steam sterilizer may achieve the required conditions within the chamber, but this does not establish that those conditions have been achieved within the most difficult-to-sterilize locations of a complex reusable medical device.

PQ provides the evidence needed to connect equipment performance with process performance.

For PQ to provide meaningful evidence, the conditions tested need to represent the actual application of the process.

AS/NZS 5369:2023 requires consideration of the reusable medical devices and other devices being processed, including the use of Product Families and representative master products.

The master product represents the challenge posed by a Product Family and allows PQ to test the process against this challenge rather than relying on arbitrary or convenient test items.

The same principle applies to the load itself.  PQ test loads should represent worst-case conditions that can reasonably be expected during routine operation. Depending on the process, this may relate to load size, weight, configuration, device complexity or other characteristics that influence cleaning, disinfection, steam penetration or drying.

This establishes an important boundary around the qualification: PQ demonstrates the process within the range of conditions that have been represented and successfully tested.

For automated cleaning and disinfection, AS/NZS 5369:2023 operates in conjunction with the ISO 15883 series.

PQ of a washer-disinfector process therefore considers both the physical process delivered by the machine and its effectiveness when processing representative reusable medical devices.

Depending on the process and equipment, assessment includes defined process parameters such as time, temperature and thermal disinfection performance, together with an assessment of cleaning efficacy.

Cleaning efficacy is particularly important because achievement of programmed machine parameters does not, by itself, demonstrate that soil has been effectively removed from the RMD.

ISO 15883 provides requirements and test methods for demonstrating cleaning performance.  Testing therefore needs to appropriately represent the devices and cleaning challenges encountered during actual reprocessing.

The result is an assessment of the cleaning and disinfection process, rather than simply a confirmation that the washer completed its cycle.

For moist heat sterilization, AS/NZS 5369:2023 operates together with ISO 17665.

The Performance Qualification of a steam sterilization process needs to establish that the specified sterilization conditions are achieved throughout the load, including locations that present the greatest challenge to steam penetration.

This is particularly important for complex reusable medical devices.

The sterilizer chamber may reach the specified sterilization temperature before the same conditions have been achieved within a challenging location of a Reusable Medical Device (RMD). Device geometry, internal pathways, construction and materials can influence the rate at which sterilization conditions are established.

PQ therefore considers thermal penetration into the reusable medical device, not simply the temperature measured within the sterilizer chamber.

Under AS/NZS 5369:2023, establishing Product Families and identifying representative master products provides the basis for assessing these different challenges.

Where a master product demonstrates greater resistance to steam penetration, the validated sterilization exposure needs to account for this challenge.

The outcome of PQ is therefore not simply evidence that the sterilizer reached temperature. It is evidence that the defined sterilization process is suitable for the Product Families represented by the qualification.

The importance of representative and repeatable evidence

Performance Qualification requires objective evidence that the process achieves its specified acceptance criteria.

Where applicable standards require repeated test cycles, those repetitions demonstrate more than a single successful outcome. They provide evidence that the required process conditions can be achieved consistently and reproducibly.

Testing therefore needs to be undertaken across complete cycles (unless partial cycle testing applies) using the defined test conditions and appropriate loads.

The measurements obtained during PQ must also be capable of supporting the conclusion being reached. Test equipment and measurement systems should therefore be appropriate for the parameter being assessed, appropriately calibrated and used in accordance with the applicable requirements.

The integrity of a PQ conclusion ultimately depends upon the integrity of the evidence supporting it.

Importantly, an endoscope storage cabinet is not a cleaning or disinfection process. Endoscopes must have been appropriately processed before entering the cabinet. Where a drying function is provided, this can supplement drying undertaken during earlier stages of reprocessing.

The Product Family and representative challenge principles also remain important. Different endoscope designs, channel configurations and connection requirements can influence drying and storage performance, and the qualification should appropriately represent the range of endoscopes routinely stored within the cabinet.

Successful PQ therefore establishes evidence that the defined drying and storage process can maintain the required conditions for the endoscopes and storage period represented by the qualification.

PQ is not complete simply because testing has been performed.

The results need to be assessed against the applicable acceptance criteria to determine whether the required process outcome has been demonstrated.

Where an acceptance criterion is not achieved, the result requires investigation.

This is an important part of the qualification process. A failed test may identify an issue relating to the equipment, cycle parameters, load, RMD characteristics, services or another part of the reprocessing process.

Simply repeating a test without understanding the original failure does not establish why the process failed or whether the underlying condition remains.

Where corrective action is required, appropriate repeat testing can then provide evidence that the identified issue has been addressed and that the affected aspect of the process now meets the applicable requirements.

This is the validated state of the process.

Changes that may affect these established conditions need to be assessed to determine whether the existing qualification remains applicable or whether additional qualification is required.

Viewed collectively, AS/NZS 5369:2023 and the International Standards that underpin it position PQ as part of a broader validation framework.

The essential technical sequence can be summarised as:

Define the process → identify the representative challenge → test the process under defined conditions → measure performance → assess against acceptance criteria → establish the validated state

This is what distinguishes Performance Qualification from equipment testing alone.

A compliant PQ provides documented evidence that the whole reprocessing process has been appropriately challenged and validated. PQ reports should also verify that test methodologies and test equipment conform to relevant standards requirements.