An alternative approach to Product Safety Testing

An alternative approach to Product Safety Testing

Matthew Larkin, TÜV Product Service Ltd
Published: March 2006 - EMC Compliance Journal

Safety Testing has traditionally been undertaken at an independent third-party test house in order to achieve the various certification marks such as CB, NRTL, GS or CE marking. This in itself has resulted in ongoing concerns such as timescales with long lead times, extended test times and the need to sometimes re-arrange test slots due to non-compliances. Another potential major issue experienced with lab based testing is the lack of communication regarding project progression and awareness of non-compliances, coupled with the issue of increasing costs due to retest, or even worse, missing a launch date due to long lead times following a non-compliance.

This article will provide the reader with the alternatives to lab based testing that are open to them, highlighting the relative merits of each alternative, namely:

  1. Testing at Manufacturer’s Premises
  2. Witnessed Manufacturer’s Testing
  3. Acceptance of Client’s Testing
  4. Supervised Manufacturer’s Testing

Testing at Manufacturer’s Premises (TMP)

One of the most popular alternative approaches to lab based safety testing is that of testing at the manufacturer’s premises. This is particularly an approach used for CE marking purposes, but can also be used as the basis for CB and other forms of Product Certification. The only actual input the manufacturer has to provide is a work area for the test engineer and a suitable power source. The In-Situ Test Engineer will bring everything else, provided by the test laboratory, hence ensuring calibration records are up-to-date, etc. Following conclusion of the testing, typically the same day as completion, the draft test report is left with the manufacturer to review. Access to this form of testing is also simple with the manufacturer only having to sign a short 2-page TMP Agreement.

The advantages of this approach are clear to see, but typically they can be categorised as follows:

  1. Shorter lead times
  2. Significantly reduced test times (typically less than 1 week) because of availability of staff to provide responses to any non-compliances
  3. Face to face interaction between engineer and client
  4. On the job training
  5. Help with tracking down component approval information
  6. Opportunity to fix non-compliances as they occur

Witness Manufacturer’s Testing (WMT)witness-process.jpg

Another alternative to lab based safety testing, assuming the manufacturer has the relevant equipment and approval, is that of Witness Manufacturer’s Testing. Again, this scheme can be used for all types of CE marking, CB and Product certification. In this instance testing is performed by the manufacturer, with their own test equipment, in their laboratory.

This testing is then witnessed by an In-Situ Engineer from the test laboratory. The manufacturer’s laboratory will have to be audited in accordance with ISO/IEC 17025 including a technical appraisal of the testing staff. A responsible person is nominated to liaise between test laboratory and manufacturer and they will be responsible for the manufacturer’s laboratory.

If CB scheme certificates are requested, the manufacturer must also undertake to participate in the CB Test Laboratory (CTL) Proficiency Testing scheme when required. Following testing, the test reports are compiled by the In-Situ Test Engineer and, assuming the reports are positive, certification can then be sought. Again, an agreement will have to be signed between the test laboratory and the manufacturer.

The advantages of this approach are also clear to see:

  1. Short lead times
  2. Shorter Test times (typically less than 1 week)
  3.  Face to face interaction between manufacturer and Test Engineer. Greater understanding of Product Safety requirements
  4. Can lead to Supervised Manufacturer’s Testing (SMT) status

Acceptance of Client’s Testing (ACT)

A third alternative to laboratory based testing, of particular use to those manufacturers with an established and mature safety test laboratory process and staff, is that of Acceptance of Client’s Testing. This is very popular for CE marking and, increasingly, other forms of product certification. With this approach, the manufacturer would carry out their own testing in their own time and in their own facility. Test reports are written by the manufacturer’s own test staff and the laboratory would be audited by the third party independent test laboratory in accordance with ISO /IEC 17025 including the technical appraisal of test staff.

Advantages:

  1. Tests can be scheduled at your own convenience
  2. Reduced tests costs
  3. Support from test laboratory
  4. Not invasive
  5. Provides the manufacturer with access to product certification marks
  6. Manufacturer’s own testing "underwritten" by 3rd part test laboratory
  7. Wide acceptance of test results

Supervised Manufacturer’s Testing (SMT)smt.jpg

Perhaps the most versatile scheme of all is that of Supervised Manufacturer’s Testing. Testing is performed by the manufacturer with their own test equipment in their laboratory. The test reports in this instance are compiled by the manufacturer and are then approved, if satisfactory, by the test laboratory. The scheme is a gradual one, with more and more responsibility passed to the manufacturer as confidence from both parties grows. A key factor that must be understood for this process is that the manufacturer’s laboratory must operate independently from other departments, with no staff having perceived, or actual, conflicts of interest within the organisation.

The qualification phase must be in place before full SMT status is granted, the steps involved in this include the following (see diagram on left):

Similar to other schemes, an agreement between test laboratory and manufacturer must be signed and coupled with the requirement for the manufacturer to nominate a responsible person to liaise between the two organisations and be responsible for the laboratory. A key benefit of this scheme is that ongoing training and support is provided by the test laboratory, including certification scheme updates, such as the addition of EMC to the CB Scheme. The manufacturer must also participate in CTL Proficiency Testing when required as part of the CB Scheme.

Advantages:

  1. Very fast
  2. Very flexible
  3. Cost effective
  4. Minimised risk
  5. Readily accepted test reports
  6. Access to certification marks and CB Certificates
  7. Ongoing support from test laboratory

Overview of ISO / IEC 17025: 2005

The international standard ISO / IEC 17025 sets out the General Requirements for the Competence of Testing & Calibration Laboratories. The main aim of ISO / IEC 17025 is to demonstrate that the laboratory:

  1. Operates a suitable quality system
  2. Are technically competent
  3. Are able to produce technically valid results

ISO 17025 addresses every element of management responsibility and activity within a laboratory environment. It is not exclusive to the Test Lab Manager or Quality Manager. The standard involves all laboratory staff whose functions relate to the quality of laboratory data generated. Typically, the requirements can be defined as per the table below:

ISO17025.jpg

Case Study

Backgroundtablet-PC.jpg

A Tablet PC manufacturer wishes to sell their product to the European Union and North America. How can the manufacturer achieve this in a fast, cost effective manner?

Solution

  1. Select an appropriate Certification Body Testing Laboratory (CBTL) that offers a Testing at the Manufacturer’s Premises Procedure for Safety & EMC
  2. Obtain CB Certification for Safety & EMC
  3. Submit CB Certificate and report to a Nationally Recognised Test Laboratory (NRTL) either directly, or via the CBTL, for straight forward North American Market Access
  4. Self declare to the EMC-D and LVD on the basis of CB Certification ( based on appropriate CB National Deviations being covered) for CE marking covering the EU
  5. As markets are realised, national certification OR just market access can be obtained using the CB Certification allowing market access without additional testing

Typical Turnaround Times

A potential 4 working weeks earlier to market than traditional laboratory based testing.

In Summary

Alternative approaches to lab based testing offer the manufacturer the opportunity to:

Reduce Timescales

  1. Exclusive access to dedicated technical experts
  2. Focuses the mind on the project
  3. Help with tracking down component approval information
  4. On the job training
  5. Opportunity to solve non-compliances as they occur
  6. No distractions
  7. No logistics issue with transporting equipment
  8. No continuous trips to and from the Test Lab to fix problems

Have more involvement in the test process

  1. When a non-compliance is raised, you are made immediately aware of the issue and can discuss it directly with our engineer rather than having to decipher a fax or e-mail
  2. Opportunity to solve non-compliances as they occur
  3. On the job training for your staff, opportunity to quiz our Engineer
  4. Increases your knowledge of testing
  5. You can control test times and duration

Reduce Costs

  1. Saves the manufacturer time
  2. More chance to achieve compliance sooner
  3. No cost involved with the transportation of equipment
  4. Opportunity to carry out own testing