The National Metrology Laboratory of South Africa

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The National Metrology Laboratory of South Africa
Feedback presentation for SAAMF meeting 05 May
2005 Eddie Tarnow Metrologist CSIR-NML
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Standards in the Automotive Industry
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Standards in the Automotive Industry
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Questions for SAACB

• 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 169492002 auditors benefit from
  additional training in Measurement System
  Analysis?

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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.
• NOTES
• 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.

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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.
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Definitions
Verification Eddies 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.
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Definitions
Validation Eddies definition.

• A set of operations which prove that a system is
  fit for its intended purpose .
• NOTES
• 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.

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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.
• NOTES
• 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.

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Definitions
Uncertainty of Measurement cont. International
Vocabulary of Basic and General Terms in
Metrology Second Edition, 1993.

• NOTES
• 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.

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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.
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Uncertainty of measurement
Result of a measurement, y, and result of
measurement, complete statement y
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Uncertainty of measurement
Example of conformance proved
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Uncertainty of measurement
Example of non - conformance proved
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Uncertainty of measurement
Example of neither conformance nor non -
conformance proved
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ISO/TS 14253-1
Uncertainty of measurement reduces conformance
range
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MSA Discussion
Is an MSAconducted?
NO
YES
Why not adequatelyaudited as partof 16949?
Why not? Notnecessary?
YES
Are 16949 auditorsexpected to do this?
An unreasonableexpectation?
Then who checks themeasurement system?
NO
YES
NO
YES
Can they do it?
Who is? The OEMs?
OEMs need to takeresponsibility control plan?
Must be done, thenby whom?
YES
YES
NO
But they dont - Action required
NO
Auditors need toput in the effort
Do they have theskills?
YES
Dont have the skills,training required
How comemeasurementproblems?
NO
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MSA Discussion

• Who conducts the MSA? (supplier/OEM?)
• Are FOP, (first of production), tests conducted?
• Who is responsible for conducting these tests,
  OEMs or suppliers?
• Who is responsible for evaluating that the
  measurement system is capable of performing the
  required measurements with the desired level of
  accuracy?
• Do these tests form part of the control plan?
• Is the understanding that an MSA addresses the
  measurement accuracy of a measurement system or
  merely its repeatability/reproducibility?