7.7 Ensuring the Validity of Results

The laboratory shall establish procedures for monitoring the validity of results, applying statistical techniques where appropriate, and taking corrective actions when necessary to maintain result accuracy and reliability.

7.7.1 Monitoring the Validity of Results

The laboratory shall have a procedure for monitoring the validity of results.

The resulting data shall be recorded in a manner that enables the detection of trends. Where practicable, statistical techniques shall be applied to review the results.

This monitoring shall be planned and reviewed and shall include, where appropriate, but not be limited to:

  • Use of reference materials or quality control materials.
  • Use of alternative instrumentation that has been calibrated to provide traceable results.
  • Functional check(s) of measuring and testing equipment.
  • Use of check or working standards with control charts, where applicable.
  • Intermediate checks on measuring equipment.
  • Replicate tests or calibrations using the same or different methods.
  • Retesting or recalibration of retained items.
  • Correlation of results for different characteristics of an item.
  • Review of reported results.
  • Intralaboratory comparisons.
  • Testing of blind sample(s).

7.7.2 Performance Monitoring

The laboratory shall monitor its performance by comparison with results from other laboratories, where available and appropriate. This monitoring shall be planned and reviewed and shall include, but not be limited to, either or both of the following:

  • Participation in proficiency testing.
    Note:

    ISO/IEC 17043 contains additional information on proficiency tests and proficiency testing providers. Providers that meet the requirements of ISO/IEC 17043 are considered to be competent.

  • Participation in interlaboratory comparisons other than proficiency testing.

7.7.3 Data Analysis and Corrective Actions

Data from monitoring activities shall be analyzed and used to control and, if applicable, improve laboratory activities.

If the results of the analysis of data from monitoring activities are found to be outside pre-defined criteria, appropriate action shall be taken to prevent incorrect results from being reported.