Proficiency testing and interlaboratory comparison

Quality managers who plan PT participation, technical managers accountable for scope coverage, and analysts who perform PT samples.

Particularly relevant to laboratories holding or seeking accreditation, where PT participation is not optional and its planning is assessed.

The syllabus below is the standard shape of the course. It is adjusted to the matrices, methods and instruments you actually run, which is agreed before delivery rather than discovered on the day.

• Why PT exists

  What external comparison demonstrates that internal QC cannot

• Planning

  Covering your accredited scope across a cycle, and evidencing that plan

• Scheme selection

  Matrix, concentration, method and provider accreditation to ISO/IEC 17043

• Scores

  z-scores, z′, zeta and En — what each accounts for and how each is read

• Handling a poor result

  Investigation, root cause, correction and demonstrating recovery

• Alternatives

  Interlaboratory comparison where no PT scheme covers the determination

Courses are written around what a delegate can do afterwards, not what was presented to them. These are the outcomes this one is built to produce.

1. 01Build a PT plan that covers your scope proportionately across a cycle.
2. 02Interpret a z-score correctly, including a satisfactory score that still deserves investigation.
3. 03Run an investigation into a questionable or unsatisfactory result that closes properly.
4. 04Arrange a defensible interlaboratory comparison where no scheme exists.

A satisfactory z-score of 1.9 is satisfactory and is also telling you something. Laboratories that read PT purely as pass or fail throw away most of the information they paid for.

The other common failure is coverage: a plan that tests the same easy determination every year while a substantial part of the accredited scope has never been externally checked. That is visible to an assessor immediately.

Delivered over 1 day, at your site or at the laboratory, in English or Arabic. Sessions are built around real records, real data and real failures rather than slides of clause numbers, and the people delivering them spend the rest of the week doing the thing being taught.

Group size is agreed in advance — practical sessions are capped so that everyone works rather than watches. An attendance certificate is issued to each delegate on completion.

Ask about any subject not listed here. If it is not something we teach well, we will say so rather than build it for the sake of the booking.