Can an ISO/TS 16949: 2002 certification programme ensure systems and processes which deliver products which conform to a technical specification?
Are customer specific MSA requirements addressed in ISO/TS 16949: 2002 audits?
To what degree are customer specific MSA requirements addressed in ISO/TS 16949: 2002 audits?
Would ISO/TS 16949:2002 auditors benefit from additional training in Measurement System Analysis?
Questions for SAACB
Definitions “ Calibration” “ International Vocabulary of Basic and General Terms in Metrology” – Second Edition, 1993.
“ Set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values realised by standards.”
The result of a calibration permits either the assignment of values of measureands to the indications or the determination of corrections with respect to the indications.
A calibration may also determine other metrological properties such as the effect of influence quantities.
The result of a calibration may be recorded in a document, sometimes called a calibration certificate or a calibration report.
Definitions “ Calibration” “ Measurement Systems Analysis” - MSA Third Edition, March 2005. “ A set of operations that establish, under specified conditions, the relationship between a measuring device and a traceable standard of known reference value and uncertainty. Calibration may also include steps to detect, correlate, report, or eliminate by adjustment any discrepancy in accuracy of the measuring device being compared.”
Definitions “ Verification” “ Eddie’s definition.” “ Periodic measurements of a traceable standard of known reference value and uncertainty for the purpose of maintaining confidence in the ability of an instrument or measuring system to continue to perform measurements with the required accuracy.”
“ A set of operations which prove that a system is fit for its intended purpose .”
A system can be a measuring instrument, a measuring system, a software programme or a spreadsheet.
The intended purpose for a measuring instrument or measuring system implies that the required measurement is performed with the desired accuracy, (uncertainty of measurement).
Validation need only be performed once, during a system commissioning or after a change has been made.
Definitions “ Uncertainty of Measurement” “ International Vocabulary of Basic and General Terms in Metrology” – Second Edition, 1993.
“ The parameter, associated with the result of a measurement, that characterises the dispersion of the values that could reasonably be attributed to the measureand.”
The parameter may be, for example, a standard deviation (or a given multiple of it), or the half-width of an interval having a stated level of confidence.
Uncertainty of measurement comprises, in general, many components. Some of these components may be evaluated from the statistical distribution of the results of series of measurements and can be characterised by experimental deviations. The other components, which can also be characterised by standard deviations, are evaluated from assumed probability distributions based on experience or other information.
Definitions “ Uncertainty of Measurement cont.” “ International Vocabulary of Basic and General Terms in Metrology” – Second Edition, 1993.
It is understood that the result of the measurement is the best estimate of the value of the measureand, and that all components of uncertainty, including those arising from systematic effects, such as components associated with corrections and reference standards, contribute to the dispersion.
Definitions “ Uncertainty of Measurement ” “ Measurement Systems Analysis” - MSA Third Edition, March 2005. “ A parameter associated with the result of a measurement that characterises the dispersion of the values that could reasonably be attributed to the measureand; the range assigned to a measurement result that describes, within a defined level of confidence, the limits expected to contain the true measurement result. Uncertainty is a quantified expression of the measurement reliability .
Uncertainty of measurement Result of a measurement, y , and result of measurement, complete statement y’
Uncertainty of measurement Example of conformance proved
Uncertainty of measurement Example of non - conformance proved
Uncertainty of measurement Example of neither conformance nor non - conformance proved
ISO/TS 14253-1 Uncertainty of measurement reduces conformance range
MSA Discussion Is an MSA conducted? Why not adequately audited as part of 16949? Why not? Not necessary? Are 16949 auditors expected to do this? An unreasonable expectation? Can they do it? Who is? The OEMs? OEMs need to take responsibility – control plan? YES YES NO NO Then who checks the measurement system? But they don’t - Action required Don’t have the skills, training required YES NO YES NO Auditors need to put in the effort YES Must be done, then by whom? NO Do they have the skills? YES How come measurement problems? YES NO