Laboratory Follow Up and Corrective
Action Checklist
Date:__________________
Laboratory: ___________________
- ICL Measurement Parameter,
Range, Uncertainty
- Was any follow up or
corrective action recommended as a part of the written analysis or the
group discussion?
- Was the reported uncertainty
comparable to other laboratory values? Was k=2 used? If at the
high end of the uncertainties, why? Could a better procedure or
instrument have been used? If at the low end, was the value
calculated correctly? Why is it smaller than the values reported by
other laboratories?
- Was a precision test
conducted as a part of the analysis? Were there any ranges with
unacceptable results? Why? If it wasn't conducted, conduct it
now: the calculation evaluates the reported (expanded at k=2)
uncertainty against the tolerances required for the equipment with any
uncertainty to tolerance ratios considered. Was the uncertainty
reported acceptable for the level of work? Could it be improved with
different equipment or procedures? Was a precision calibration done
when not requested as a part of the ILC?
- Was a Youden analysis or En
analysis conducted? Were the reported values outside the circle on
the Youden chart or was the En value greater than 1? If values were
outside the circle or the E(n) value is greater than 1, this indicates a
measurement bias. Was bias observed on other types of charts?
If a bias was present, are there any overriding reasons for it? An
investigation generally needs to be conducted looking for common errors
and problems: e.g., apparent mass vs brass rather than conventional
mass, incorrect values for the standard used, errors in software used for
calculations, deviations from SOPs (using tap water for gravimetric calibration),
need for calibration of standards.
- Conduct an investigation of
bias (even if values passed the Youden and E(n) analyses) against internal
calibrations, control charts, PMAP charts, previous round robin results or
recent calibrations to find out if there is correlation of the ILC data
with internal laboratory data.
- Are there corrective actions
that need to be taken by the laboratory now? By what deadline will
concerns be resolved?
- Enter summary data into a
tracking system (such as PMAP) to track bias on specific standards over
time (e.g., 1 kg).