ISO/IEC 17025:2017 requires in article 7.2.2.1 that the laboratory shall validate non-standard methods, laboratory-developed methods and standard methods used outside their intended scope or otherwise modified. Because of this all standard methods just have to be verified due to article 7.2.1.5.
Within this context the definition of standard methods seems to be very important.
Article 7.2.1.4 gives an idea of the intention, because there is mentioned that when the customer does not specify the method to be used, the laboratory shall select an appropriate method and inform the customer of the method chosen. Methods published either in international, regional or national standards, or by reputable technical organizations, or in relevant scientific texts or journals, or as specified by the manufacturer of the equipment, are recommended.
Also the note within article 7.2.1.3 gives an idea that international, regional or national standards or other recognized specifications that contain sufficient and concise information on how to perform laboratory activities do not need to be supplemented or rewritten as internal procedures if these standards are written in a way that they can be used by the operating personnel in a laboratory.
a) If the customer of a laboratory states in the order that a specific method written by this customer (factory standard of e.g. a car manufacturer, railway company, power plant operator) or by an assocoation of manufacturers or other technical organizations, this specific method is then to be regarded as standard methods within the meaning of ISO/IEC 17025, which only be need to be verified?
b) Or are such customer-specific methods to be validated by each laboratory, knowing full well that the laboratories must work uniformly according to this procedure?
A method can be considered as a “standard” method if it meets the criteria included in the definition stated in ISO/IEC Guide 2:2004 cl. 3.2 and EN 45020:2006 cl. 3.2:
“Standard: document, established by consensus and approved by a recognized body, that provides, for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context
NOTE Standards should be based on the consolidated results of science, technology and experience, and aimed at the promotion of optimum community benefits.”Standard methods are expected to include an indication of their performance characteristics and should be publicly available.