IQ, OQ and PQ for lab equipment: what NABL 112A actually asks
What IQ, OQ and PQ each contain for lab analyzers, who performs which stage, when to re-qualify, and the records NABL 112A and ISO 15189 clause 6.4.3 expect.
Last reviewed 12 August 2026
A new analyzer arrives, the vendor's engineer spends a day with it, results start flowing, and six months later an assessor asks a simple question: show me the evidence this instrument was fit for use before you reported the first patient result from it. A delivery note and a warranty card do not answer that question. IQ, OQ and PQ do — three stages, each answering one thing.
Where the requirement comes from
Two places, and they stack. ISO 15189:2022 clause 6.4.3 requires acceptance testing: the laboratory verifies that equipment is capable of the necessary performance before it goes into service, and again after repair before it returns. NABL 112A goes further and names the framework: IQ, OQ and PQ shall be performed and documented at installation of new equipment, on change of existing equipment, and on change of premises — with performance verification covering, at minimum, accuracy, precision, linearity and carryover.
So for a NABL laboratory this is not one interpretation among several. The three stages, documented, are the expectation an assessor arrives with.
IQ — Installation Qualification
Was it installed the way the manufacturer specified?
- Delivery checked against the purchase order — model, serial number, accessories, manuals
- Physical damage inspection recorded, not just performed
- Location meets the manufacturer's requirements: bench space, clearance, temperature and humidity range
- Utilities verified: supply voltage and stability, UPS capacity, water quality where required, drainage, LIS network point
- Software installed at the stated version; user accounts and access levels created
- Manufacturer's installation checklist completed and signed by the installing engineer
What the file keeps: A signed installation report with the serial number, location, utility readings and the engineer's name on it.
OQ — Operational Qualification
Does every function work across its stated range?
- Every operating mode exercised: sample types, dilutions, stat handling, rerun logic
- Alarms and interlocks provoked deliberately and their responses recorded
- Temperature, pressure or speed verified at the operating points, against a traceable reference where applicable
- Barcode reading, sample identification and LIS transmission tested end to end
- Error recovery tested: power interruption, aborted run, clot or bubble handling as applicable
What the file keeps: A functional test record showing what was exercised, the acceptance limits, and the observed values — not a row of ticks.
PQ — Performance Qualification
Does it produce dependable results under your routine conditions, run by your people?
- Precision estimated by repeat measurement at clinically relevant levels
- Accuracy checked against reference material, EQA samples, or patient comparison with the outgoing method
- Linearity verified across the reportable range you intend to claim
- Carryover checked where the analyser design makes it possible
- Run by the laboratory's own staff under routine conditions — not by the vendor on a curated sample set
What the file keeps: The data and the decision: observed performance against the manufacturer's claims and your lab's acceptance criteria, signed by whoever authorised routine use.
The split that goes wrong most often
IQ and OQ are usually the manufacturer's work — their engineer, their specifications, their service tools. PQ is yours: your staff, your samples, routine conditions. The failure mode is assuming the vendor's visit covered everything. It usually covered IQ, part of OQ, and none of PQ — and the only evidence left behind is a job card that says “installed and working”. Ask for the qualification protocol and the signed report before the engineer leaves; they exist for every serious analyzer.
Re-qualification: the triggers
Qualification is not a birth certificate; it describes the instrument in a place, at a software version, in a condition. Move it, repair it substantially, upgrade its software, or change the premises around it, and the description no longer holds. Each trigger needs a proportionate re-check — sometimes the full sequence, often an abbreviated one — and the reasoning belongs in the equipment file alongside the original reports (NABL 112A names these same triggers explicitly).
Where the records live
Clause 6.4.7 requires the equipment file to hold the acceptance and entry-into-service evidence for the instrument's whole life. In practice that means: the qualification protocols, the raw data, the signed reports, any deviations and their resolution, and the named sign-off that authorised routine use. Scattered across a vendor's email thread and a drawer, these records exist but cannot be produced; the difference matters exactly once, in front of an assessor.
Common questions
What is IQ, OQ and PQ for laboratory equipment?
Three documented stages of proving an instrument fit for use. Installation Qualification (IQ) verifies it was installed to the manufacturer's specification. Operational Qualification (OQ) verifies every function works across its stated range. Performance Qualification (PQ) demonstrates it produces dependable results under the laboratory's own routine conditions. The vocabulary comes from pharmaceutical validation and is now standard across diagnostic laboratories.
Does NABL require IQ, OQ and PQ?
Yes. NABL 112A requires IQ, OQ and PQ to be performed and documented at installation of new equipment, on change of existing equipment, and on change of premises — and names accuracy, precision, linearity and carryover as the minimum performance verification. ISO 15189:2022 clause 6.4.3 separately requires acceptance testing before any equipment is placed into service.
Who performs each qualification — the vendor or the lab?
IQ and OQ are usually executed by the manufacturer's installing engineer, because they require the manufacturer's specifications and service tools. PQ belongs to the laboratory: it must be run by your own staff, on your samples, under routine conditions. Either way the laboratory owns the records and the acceptance decision — a vendor's "installed OK" on a delivery note is not a qualification.
When does equipment need re-qualification?
When something that the original qualification depended on changes: the instrument is moved, a major repair or part replacement is carried out, software is upgraded, or the premises change. The scope can be proportionate — a relocation may need IQ plus an abbreviated PQ rather than the full sequence — but the decision and its justification belong in the equipment file.