IJCA Vol 5 Issue 1 - Flipbook - Page 36
The International Journal of Conformity Assessment
certificates, scopes, and competence). “Official
test numbers” alone do not prove traceability;
uncertainty and the documented chain do.
Provider. Providing support for the claim of
traceability of the result of a measurement or
value of a standard is the responsibility of the
calibration provider. Calibration reports and
certificates must contain a traceability statement.
User. Assessing the validity of a claim of
traceability is the responsibility of the user of that
result or value. Verifying claims of traceability often
includes obtaining a calibration directly from a
national metrology institute or another laboratory
that has achieved recognition or accreditation
through a recognized accrediting body.
Use of, or reference to, official test numbers of a
national metrology institute. Having an authentic
test number does not provide assurance or
evidence that the measurement value provided by
another organization is traceable. Not only must
there be an unbroken chain of comparisons, but
each measurement must be accompanied by
a statement of uncertainty associated with the
value. Test report numbers should not be used nor
required as proof of the adequacy or traceability of
a test or measurement. National and international
standards dealing with test and measurement
quality requirements, such as ANSI/NCSL Z 540-1,
ISO 10012, ISO/IEC 17025 and the ISO 9000 series
do not require the use or reporting of specific test
numbers to establish traceability.
Relationship to Accreditation and
Recognition
Accreditation bodies (e.g., NVLAP, IAS, ANAB,
A2LA, UKAS) evaluate laboratory compliance
against ISO/IEC 17025 and related standards;
traceability is a foundational requirement
embedded in those criteria. Transparent
accreditation processes, proficiency testing, and
surveillance support ongoing confidence and
reduce barriers to acceptance of results across
borders.
Advantages and Challenges of Traceability
Traceability offers significant benefits for
organizations and laboratories, but it also
introduces challenges that require planning,
resources, and ongoing technical competence.
Advantages
Global acceptance of results: Facilitates
conformity assessment, procurement, and
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2026 | Volume 5, Issue 1
regulatory compliance through mutual recognition
and common references.
Decision con昀椀dence: Known uncertainty lets
decision-makers align risk and guard banding with
speci昀椀cations.
Process comparability and uniform
measurements: Enables consistent measurements
across time, sites, and organizations.
Quality assurance leverage: Integrates naturally
with measurement assurance programs and
management systems.
Challenges
Cost and administrative burden: Periodic
calibration, documentation, and accreditation/
recognition activities consume time and
resources.
Complexity: Branched hierarchies (multi-input
models) require careful uncertainty propagation
and parallel traceability of inputs.
False con昀椀dence risks: Traceability does not
guarantee that the uncertainty is adequate or
that mistakes are absent; competence and 昀椀t‑for‑
purpose evaluation remain essential.
Good Practices for Laboratories and
Assessors
Maintain explicit traceability charts for each
quantity (length, mass, temperature, pressure,
electrical, time/frequency), recording standards,
uncertainty, and intervals.
Verify provider competence (accreditation status/
scope, participation in intercomparisons) rather
than relying on test numbers.
Ensure SI realization linkage to current
de昀椀nitions; for evolving realizations (e.g., post‑
IPK frameworks), manage transitions with
documented corrections/uncertainty.
Integrate with management systems (QMS) to join
technical traceability with process controls and
continual improvement.
Human Factors
Traceability is ultimately delivered by people: clear
procedures, training, attention to environmental
in昀氀uences, and correct use of instruments are as
important as the references themselves. Visual
tools—pyramids, 昀氀ow charts, and completed traceability charts—help technicians, engineers, and
assessors reach a shared understanding of where
the number comes from and how con昀椀dent we can
be in it.
