Human error study as a part of method validation task

The lecture is an overview of recently published IUPAC/CITAC Guide: Classification, Modeling and Quantification of Human Errors in a Routine Analytical Laboratory (IUPAC Technical Report). The classification includes commission errors (mistakes and violations) and omission errors (lapses and slips) by different scenarios at different steps of the chemical analysis. A Swiss cheese model is used for characterization of the error interaction with a laboratory quality system. Quantification of human errors in chemical analysis, based on expert judgments, i.e. on the expert(s) knowledge and experience, is applied. Monte Carlo simulation of the expert judgments was used for determination of distributions of the error quantification scores (scores of likelihood and severity, and scores of effectiveness of a laboratory quality system against the errors). Residual risk of human errors, remaining after the error reduction by the laboratory quality system, and consequences of this risk for quality and measurement uncertainty of chemical analytical results are discussed. Examples are provided using expert judgments on human errors in pH measurement of groundwater, multi-residue analysis of pesticides in fruits and vegetables, and elemental analysis of geological samples by inductively coupled plasma mass spectrometry.

Results of the human error study would be useful for validating the analytical method and formulation of the SOP, as well as for training (how to avoid the errors) and for supervision. The map of possible human error scenarios, included in the validation report, may be useful also as a check list for prior assessment of an analyst before assigning the task, etc.