title: Monte Carlo simulation of expert judgments on human errors in chemical analysis--a case study of ICP-MS.
abstract: Monte Carlo simulation of expert judgments on human errors in a chemical analysis 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 in prevention of the errors). The simulation was based on modeling of an expert behavior: confident, reasonably doubting and irresolute expert judgments were taken into account by means of different probability mass functions (pmfs). As a case study, 36 scenarios of human errors which may occur in elemental analysis of geological samples by ICP-MS were examined. Characteristics of the score distributions for three pmfs of an expert behavior were compared. Variability of the scores, as standard deviation of the simulated score values from the distribution mean, was used for assessment of the score robustness. A range of the score values, calculated directly from elicited data and simulated by a Monte Carlo method for different pmfs, was also discussed from the robustness point of view. It was shown that robustness of the scores, obtained in the case study, can be assessed as satisfactory for the quality risk management and improvement of a laboratory quality system against human errors.
authors.affiliation: National Physical Laboratory of Israel (INPL), Danciger "A" Bldg, Givat Ram, 91904 Jerusalem, Israel. Electronic address: ilya.kuselman@gmail.com.
authors.forename: Ilya
authors.initials: I
authors.lastname: Kuselman
authors.affiliation: Istituto Nazionale di Ricerca Metrologica (INRIM), 91 Strada delle Cacce, 10135 Turin, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pennecchi
authors.affiliation: National Physical Laboratory of Israel (INPL), Danciger "A" Bldg, Givat Ram, 91904 Jerusalem, Israel.
authors.forename: Malka
authors.initials: M
authors.lastname: Epstein
authors.affiliation: International Atomic Energy Agency (IAEA), Vienna International Centre, PO Box 100, A-1400 Vienna, Austria.
authors.forename: Ales
authors.initials: A
authors.lastname: Fajgelj
authors.affiliation: Laboratory of Government Chemist Ltd (LGC), Queens Road, Teddington TW11 0LY, Middlesex, UK.
authors.forename: Stephen L R
authors.initials: SL
authors.lastname: Ellison
keywords: Chemical analysis; Expert judgment; Human error; ICP–MS; Monte Carlo simulation