INTERNATIONAL STANDARD ISO 14253 1.pdf
INTERNATIONAL STANDARD ISO 14253 1.pdf ->>> https://urlca.com/2tyKWF
What is ISO 14253-1 and why is it important for geometrical product specifications
ISO 14253-1 is a general geometrical product specification (GPS) standard that defines the rules and principles for the verification of workpieces and populations of workpieces against specifications. It applies to specifications defined in general GPS standards prepared by ISO/TC 213, such as upper and lower specification limits, maximum material requirements, least material requirements, envelope requirements, etc.
ISO 14253-1 is important because it provides a common framework for the evaluation of conformity of workpieces and populations of workpieces to specifications. It also specifies the uncertainty of verification results and how to use them for decision making. By following ISO 14253-1, manufacturers and customers can ensure that their products meet the intended quality and functionality.
ISO 14253-1 was first published in 1998 and revised in 2017. It is part of the ISO 14253 series that covers various aspects of GPS verification. A list of all parts in the ISO 14253 series can be found on the ISO website[^1^].
How to verify conformity and nonconformity with specifications according to ISO 14253-1
ISO 14253-1 specifies two default decision rules for verifying conformity and nonconformity with specifications, based on the conformance probability limit and the nonconformance probability limit. These limits are defined as the minimum probabilities of conformity and nonconformity, respectively, that are acceptable for making a decision.
The rule for verifying conformity with specifications states that a workpiece or a population of workpieces is considered to conform to a specification if the probability of conformity is greater than or equal to the conformance probability limit. The default value for the conformance probability limit is 95 %, unless otherwise agreed by the parties involved.
The rule for verifying nonconformity with specifications states that a workpiece or a population of workpieces is considered to not conform to a specification if the probability of nonconformity is greater than or equal to the nonconformance probability limit. The default value for the nonconformance probability limit is 50 %, unless otherwise agreed by the parties involved.
ISO 14253-1 also defines an uncertainty zone as the range of measured values where neither conformity nor nonconformity can be verified with sufficient confidence. In this case, ISO 14253-1 recommends to use additional information or actions to reach a decision, such as repeating measurements, reducing measurement uncertainty, applying correction factors, etc.
How to apply ISO 14253-1 in a supplier/customer relationship
ISO 14253-1 also provides guidance on how to apply the decision rules in a supplier/customer relationship, where different parties may have different interests and responsibilities regarding the verification of conformity and nonconformity with specifications.
ISO 14253-1 recommends that the supplier verifies the conformity of the workpieces or populations of workpieces before delivery, using the rule for verifying conformity with specifications. The supplier should also provide the customer with information about the measurement uncertainty and the conformance probability limit used for verification.
ISO 14253-1 recommends that the customer verifies the nonconformity of the workpieces or populations of workpieces after delivery, using the rule for verifying nonconformity with specifications. The customer should also use the same measurement uncertainty and nonconformance probability limit as the supplier, unless otherwise agreed by the parties involved.
ISO 14253-1 states that if a dispute arises between the supplier and the customer regarding the conformity or nonconformity of a workpiece or a population of workpieces, they should try to resolve it by using additional information or actions, such as repeating measurements, reducing measurement uncertainty, applying correction factors, etc. 061ffe29dd