1. TRAINING PROGRAM ON Decision Rule as per ISO/IEC 17025:2017

2. Decision Rule 1.ISO 14253-1:1998 –Geometrical Product Specifications (GPS) -Inspection by measurement of workpieces and measuring equipment -Part 1: Decision rules for proving conformance or non- conformance with specifications The 2.ASME B89.7.3.1-2001 Guidelines for Decision Rules: considering Measurement Uncertainty in Determining Conformance with Specifications. 3.ILAC G-8:03/2009 “Guidelines on the reporting of compliance to Specification” 4.ISO GUIDE 98-4 5.JCGM 106:2012 “Evaluation of Measurement Data-the Role of measurement uncertainty in conformance assessment” 6.Eurachem/CITAC Guide “Use of uncertainty information in compliance assessment

3. Requirement addressed in ISO/IEC 17025:2017 7.8.6 Reporting statements of conformity 7.8.6.1 When a statement of conformity to a specification or standard is provided, the laboratory shall document the decision rule employed, taking into account the level of risk (such as false accept and false reject and statistical assumptions) associated with the decision rule employed and apply the decision rule. NOTE Where the decision rule is prescribed by the customer, regulations or normative documents, a further consideration of the level of risk is not necessary. 7.8.6.2 The laboratory shall report on the statement of conformity, such that the statement clearly identifies: a)to which results the statement of conformity applies; b)which specifications, standards or parts thereof are met or not met; c)the decision rule applied (unless it is inherent in the requested specification or standard) NOTE For further information see ISO/IEC Guide 98-4.”

4. What is a Decision Rule? The meaning of decision rule is defined by ISO 17025:2017, it states that: “rule that describes how measurement uncertainty is accounted for when stating conformity with a specified requirement” Decision Rule is a statement of rules describing how you will use the Measurement Uncertainty (MU) in relation to the measurement results and tolerance to come up with a pass or failed decision. It is the same with an instruction, telling you what to do in order to decide if an instrument has passed or failed based on a criteria.

5. Implementation of Decision Rule as per ISO/IEC 17025:2017

6. Statement of conformity A conformity statement or a statement of conformity is an expression that clearly describes the state of compliance or non-compliance to a specification, standard, or requirement. Decision rules for proving conformance or non-conformance with specifications makes a differentiation whether conformance or non-conformance shall be determined with a high probability. The expanded measurement uncertainty U and a confidence level of approx. 95% (expansion factor k = 2) will generally be considered to be adequate. There may be cases that would require a higher confidence level of e.g. 99% (expansion factor k = 3) be chosen

7. Statement of Conformity Where the measurement uncertainty interval is overlapping the limit value, implies a careful analysis that should establish objective criteria (decision rule) to accept the measurement having part of the uncertainty interval outside the tolerance ;

8. Statement of Conformity Guard Band-The magnitude of the offset from the specification limit to the acceptance or rejection zone boundary.

9. Types of Statements of conformity Compliance: If the specification limit is not breached by the measurement result plus the expanded uncertainty with a 95% coverage probability, then compliance with the specification can be stated. This can be reported as “Compliance” The measurement result is within (or below) the specification limit when the measurement uncertainty is taken into account”. In calibration this is often reported as “Pass

10. Non-compliance: If the specification limit is exceeded by the measurement result minus the expanded uncertainty with a 95% coverage probability, then noncompliance with the specification can be stated. This can be reported as “Non-compliance” –The measurement result is outside (or above) the specification limit when the measurement uncertainty is taken into account”. In calibration this is often reported as “Fail”;

11. Indeterminate If the measurement result plus/minus the expanded uncertainty with a 95 % coverage probability overlaps the limit, it is not possible to state compliance or non-compliance. The measurement result and the expanded uncertainty with a 95 % coverage probability should then be reported together with a statement indicating that neither compliance nor non- compliance was demonstrated

12. How to Implement These Decision Rules in Your Laboratory “Where statements of conformity are made in the report, the following decision rules are applied: PASS – Results ± expanded uncertainty within limits/specifications PASS‡ – Results are within limits/specifications but overlap when expanded uncertainty is taken into account FAIL‡ – Results exceed limits/specifications but overlap when expanded uncertainty is taken into account FAIL – Results ± expanded uncertainty exceeds limits/specifications”