The Evolution of Guide 25 into ISO Standard 17025

By Daniel D. Hoolihan

TÜV Product Service (New Brighton, MN)

Accreditation of EMC laboratories has taken on increasing importance in the last several years. This development has resulted in part from FCC's decision to allow self-declaration of personal computer emissions as a legitimate, even preferred, procedure for conformity assessment—if the testing is performed at an accredited laboratory. This emphasis on accreditation has become formalized with the rising importance of mutual recognition agreements between the United States and the European Union and between the United States and the Asian-Pacific Economic Community.

Currently, the relevant document for lab accreditation is the ISO/IEC Guide 25, "General Requirements for the Competence of Testing and Calibration Laboratories."¹Reflecting the increasing worldwide importance of this subject, Guide 25 is now being revised as ISO Draft International Standard 17025, using the same title.

More than 123 pages of comments were received from interested parties from around the world in response to the latest draft (number seven) of the new standard. Working Group 10 of the ISO Conformity Assessment Committee (CASCO) met in March 1999 to resolve technical and administrative issues arising from the many comments. The latest version of the Draft International Standard (DIS) 17025 should be released for final vote in the summer of 1999. If all goes well, the new standard could be in the marketplace by first quarter 2000.

Two much-debated issues in the draft standard are tolerance testing or guardbanding and measurement traceability. The first issue addresses the prevention of false acceptance of out-of-tolerance measurements, while the second issue is important for calibration traceability. (The United States voted against the latest draft of 17025 because it didn't like the wording of section 5.6 on measurement traceability.)

In general, the requirements in the draft standard are more mandatory in nature than the recommendations of the guide. The organization of the draft standard has changed to reflect this difference. That is, as discussed below, the main body of the standard is divided into three parts: initial requirements, management requirements, and technical requirements.

Initial Requirements of ISO 17025

The opening sections of 17025 are entitled Introduction, Scope, Normative References, and Terms/Definitions. The introduction is similar to the Guide 25 introduction in that it refers to ISO 9001 and 9002 and specifies that certification to those standards does not necessarily demonstrate technical competence. Of course, technical EMC competence is the key to producing technically valid testing results.

The section on scope is very similar to that of Guide 25. It specifies the general lab requirements and the organizations to which it is applicable, including first-, second-, and third-party laboratories. The normative references include ISO/IEC Guide 2, VIM, ISO 9001, and ISO 9002. The terms and definitions section includes best measurement capability as the only definable term, and it only applies to calibration labs. This section also references ISO/IEC Guide 2, VIM, and ISO 8402.²

Management Requirements

This section covers the basic material and content of ISO 9001: 1994. The management requirements of DIS 17025 are very similar to those of ISO/IEC Guide 25 and EN 45001. Few changes have occurred in the area of lab operational guidelines from an administrative perspective.

4.1 Organization and Management. This section of 17025 stresses the fact that "the lab can be held legally responsible." The lab must be organized so that it can carry out its work at permanent or temporary facilities. If the lab is part of a larger organization, the responsibilities must be carefully divided to avoid conflicts of interest.

The lab must have management and technical personnel with the authority and resources needed to do the EMC testing. The lab personnel must be free from any undue pressures that could adversely affect the work. The lab must have policies to protect the clients' confidential information and they must have an organizational chart that specifies the interrelationships of all personnel. The lab must also have a technical manager and a quality manager.

4.2 Quality System. The lab management staff must establish a quality system and document the lab's pertinent policies and procedures. The quality system will be recorded in a manual that includes a policy statement by the chief executive.

4.3 Document Control. The lab must have procedures to control all documents that are part of its quality documentation. A master list of issued quality system documents must be kept by the lab. Changes to documents shall be reviewed and approved by the same authority performing the original review.

4.4 Review of Report, Tenders, or Contracts. The lab shall establish and maintain procedures for the review of requests, tenders, or contracts.

4.5 Subcontracting of Tests and Calibrations. Work may be subcontracted to competent subcontractors for special tests requiring extra technical expertise.

4.6 Purchasing of Services and Supplies. The lab shall use only such services and supplies that are at a level of quality sufficient to create reliable test results.

4.7 Service to the Client. The lab shall allow clients to monitor the performance of the lab during the EMC testing process.

4.8 Complaints. The lab shall have a policy and appropriate procedures for resolving customer complaints.

4.9 Control of Nonconforming Testing Work. The lab shall have procedures to implement when its work does not conform with its own procedures or the agreed upon requirements with the client.

4.10 Corrective Action. The lab shall have a policy for implementing corrective action when departures from technical procedures have been identified.

4.11 Preventive Action. Opportunity for needed improvement shall be identified and the necessary action plans should be developed and implemented.

4.12 Records. The lab shall have procedures for quality and technical records including security and confidence measures.

4.13 Internal Audits. The lab shall periodically (in accordance with a predetermined schedule) perform internal audits of its activities.

4.14 Management Reviews. The executive management of the laboratory shall periodically review the lab's operations to ensure continuing suitability and effectiveness.

Technical Requirements

Measurement uncertainty is stressed more heavily in the draft standard than in Guide 25. All other technical sections of the two are very similar.

5.1 General. Seven technical factors (5.2 – 5.8) contribute to the total conformity of measurement of the laboratory.

5.2 Personnel. The technical personnel must be qualified for each specific test on the basis of appropriate training, education, experience, or demonstrated skills. The lab shall maintain current job descriptions for all personnel.

5.3 Accommodations and Environmental Conditions. Lab facilities shall allow current performance of EMC tests by appropriate separation of emission and immunity test areas.

5.4 Test Methods. The lab shall use appropriate test procedures including estimation of measurement uncertainty. The lab shall have instructions on the use and operation of all relevant test equipment.

5.5 Equipment. The lab shall have all necessary test equipment for performing the EMC tests in its scope of accreditation. Records shall be maintained on lab equipment, especially the calibration histories.

5.6 Measurement Traceability. All equipment shall be calibrated before being put into service. The calibration must be traceable to the Systems International (SI) units of measurement. Calibration certificates shall include measurement uncertainty.

5.7 Sampling. When a lab does EMC sampling, it must have a plan and procedure for the sampling process.

5.8 Handling and Transportation for Test Items. The lab shall have procedures for transporting and handling test items including procedures for marking and identifying the test items.

5.9 Assuring the Quality of Test Results. The lab shall assure the quality of results by monitoring test results using statistical techniques and other established methods.

5.10 Reporting the Results. The test results shall be reported accurately, clearly, unambiguously, and objectively in the form of a test report or a test certificate.

Conclusion

The organization of DIS 17025 emphasizes the distinction between management requirements and technical requirements for an accredited laboratory. Because the technical requirements are called out in explicit detail, a lab that complies with ISO 17025 is essentially also ISO 9001 compliant. By contrast, a lab certified to ISO 9001 may or may not also comply with the technical criteria of ISO 17025.

References

1. International Organization for Standardization, ISO/IEC Guide 25: "General Requirements for the Competence of Calibration and Testing Laboratories," 3rd ed., Geneva, 1990.

2. International Organization for Standardization, ISO 8402: "Quality Management and Quality Assurance—Vocabulary," 2nd ed., Geneva, 1994.