ISO 17025 Measurement Uncertainty Evaluation Checklist for Pharmaceutical Labs

The main steps include: 1) Specifying the measurand, 2) Identifying all significant sources of uncertainty, 3) Quantifying each uncertainty component, 4) Calculating the combined standard uncertainty, 5) Determining the expanded uncertainty, and 6) Reporting the result with its associated uncertainty.

Laboratories should conduct a systematic review of the entire measurement process, considering factors such as sampling, sample preparation, instrument calibration, environmental conditions, operator variability, and method parameters. Techniques like cause-and-effect diagrams (Ishikawa diagrams) can be useful in this process.

Common methods include Type A evaluation (based on statistical analysis of series of observations) and Type B evaluation (based on other information such as calibration certificates, literature data, or expert judgment). Advanced techniques like Monte Carlo simulations may also be used for complex measurement models.

The checklist includes items to ensure that measurement uncertainty is reported in a clear and unambiguous manner, typically as an expanded uncertainty with a stated coverage factor and confidence level. It also addresses the need to consider client requirements and regulatory guidelines when deciding on the format and detail of uncertainty reporting.

While ISO 17025 doesn't specify a fixed frequency, the checklist recommends regular reviews, typically annually or when significant changes occur in the measurement process, equipment, or environmental conditions. It also suggests periodic verification through participation in proficiency testing or inter-laboratory comparisons.