Страница 4: ДСТУ EN ISO/IEC 17043:2014. Conformity assessment - General requirements for proficiency testing (61382)

NOTE This does not preclude the proficiency testing provider utilizing advice or assistance from any advisors, experts or steering group.

NOTE This notification can, for example, take the form of a statement in the proficiency testing scheme documentation, such as the following: “Various aspects of the proficiency testing scheme can from time to time be subcontracted. When subcontracting occurs, it is placed with a competent subcontractor and the proficiency testing provider is responsible for this work.”

NOTE It is understood that some proficiency testing providers can be required to implement their purchasing procedures in accordance with policies defined by their parent company or a host organization.

NOTE Examples of the types of feedback include customer satisfaction surveys and review of proficiency testing reports with customers.

The proficiency testing provider shall have a policy and follow a procedure for the resolution of complaints and appeals received from participants, customers or other parties. Records shall be maintained of all complaints, appeals, investigations and corrective actions taken by the proficiency testing provider.

1. the responsibilities and authorities for the management of nonconforming work are designated and actions (including halting work of ongoing programmes and withholding reports, as necessary) are defined and taken when nonconforming work is identified;

2. an evaluation of the significance of the nonconforming work is made;

3. a decision on the need for action and timescale is taken immediately, together with any decision about the acceptability of the nonconforming work;

4. proficiency testing scheme participants and other customers, as appropriate, are informed and the nonconforming proficiency test items or reports already sent to participants are recalled or disregarded; and

5. the responsibility for authorization of the resumption of work is defined.

NOTE Identification of nonconforming work or problems with the management system or with technical activities can occur at various places within the management system and technical operations. Examples are participant complaints, management reviews and internal or external audits, quality control, preparations of proficiency test items, homogeneity and stability tests, data analysis, instructions to participants, and materials handling and storage.

The proficiency testing provider shall continually improve the effectiveness of its management system through the use of the quality policy, quality objectives, audit results, analysis of data, corrective and preventive actions and management review.

The proficiency testing provider shall establish a policy and procedure(s) and shall designate appropriate personnel for implementing corrective actions when nonconforming work or departures from the policies and procedures in the management system or technical operations have been identified.

NOTE See 5.9.1, Note.

The procedure for corrective action shall start with an investigation to determine the root cause(s) of the problem.

NOTE Cause analysis is the key and sometimes the most difficult part in the corrective action procedure. Often, the root cause is not obvious and thus a careful analysis of all potential causes of the problem is required Potential causes could include customer requirements, proficiency test items and their specifications, methods and procedures, staff skills and training, consumable supplies, preparations of proficiency test items, homogeneity and stability tests, statistical design, instructions to participants, and materials handling and storage.

from corrective action investigations.

The proficiency testing provider shall monitor the results to ensure that the corrective actions taken have been effective.

Where the identification of nonconforming activities or departures from authorized procedures cast doubts on the compliance of the proficiency testing provider with its own policies and procedures, or on its compliance with this International Standard, the proficiency testing provider shall ensure that the appropriate areas of activity are audited in accordance with 5.14 as soon as possible.

NOTE Such additional audits often follow the implementation of the corrective actions to confirm their effectiveness. An additional audit can be necessary only when a serious issue or risk to the proficiency testing scheme is identified.

NOTE Records can be in the form of any type of media, such as hard copy or electronic storage media.

1. results of homogeneity and stability testing;

2. instructions to participants;

3. participants' original responses;

4. collated data for statistical analysis;

5. information required for reports (see 4.8); and

6. final reports (summary or individual, or both).

NOTE 1 It is advisable to retain sufficient information to establish an audit trail for the processing of results from proficiency testing rounds.

NOTE 2 Technical records are accumulations of data and information which result from carrying out all proficiency testing activities. They can include forms, contracts, work sheets, work books, check sheets, work notes, sub-contractor reports and participant feedback.

1. identify the change and date of alteration;

2. avoid loss of original data; and

3. identify the person making the alteration.

NOTE It is advisable that the programme for internal auditing of the management system be completed every 12 months.

1. the suitability of policies and procedures;

2. reports from management and supervisory personnel;

3. the outcome of recent internal audits;

4. corrective and preventive actions;

5. assessments by external bodies;

6. changes in the volume and type of work;

7. customer, advisory group or participant feedback;

8. complaints and appeals;

9. recommendations for improvement; and

10. other relevant factors, such as resources and staff training.

NOTE 1 A typical period for conducting a management review is once every 12 months.

NOTE 2 Results can feed into the proficiency testing provider's planning system and can include the objectives and action plans.

NOTE 3 A management review includes consideration of related subjects at regular management meetings.

NOTE 4 Where the proficiency testing provider is part of a larger organization, it can be appropriate to hold a separate review meeting to cover proficiency testing activities. .

Annex A
(informative)

Types of proficiency testing schemes

A.1 General

Proficiency testing has become an essential aspect of laboratory practice in all areas of testing, calibration and inspection. Proficiency testing schemes vary according to the needs of the sector in which they are used, the nature of the proficiency test items, the methods in use and the number of participants. However, in their simplest form, most proficiency testing schemes possess the common feature of comparison of results obtained by one laboratory with those obtained by one or more different laboratories.

The nature of the test or measurement performed in proficiency testing schemes governs the method of comparing performance. There are three basic types of laboratory examinations: quantitative, qualitative and interpretive.

• The results of a quantitative measurement are numerical and are reported on an interval or a ratio scale. Tests for quantitative measurement may vary in their precision, trueness, analytical sensitivity, and specificity. In quantitative proficiency testing schemes, numerical results are usually analysed statistically.

• The results of qualitative tests are descriptive and reported on a categorical or ordinal scale, e.g. identity of micro-organisms, or by identification of the presence of a specific measurand (such as a drug or a grading of a characteristic). Assessment of performance by statistical analysis may not be appropriate for qualitative examinations.

• In interpretive tests, the “proficiency testing item” is a test result (e.g. a descriptive morphology statement), a set of data (e.g. to determine a calibration line) or other set of information (e.g. a case study), concerning an interpretative feature of the participant's competence.

Other proficiency testing schemes have additional features depending on their objective, as outlined in definition 3.7, Note 1, a) to h). Some common applications of those types of proficiency testing are discussed below and illustrated in Figure A. 1. These schemes may be “single occasion” and performed once, or “continuous” and performed at regular intervals.

A.2 Sequential participation schemes

Sequential participation schemes (sometimes known as measurement comparison schemes) involve the proficiency test item being circulated successively from one participant to the next (i.e. sequential participation), or occasionally circulated back to the proficiency testing provider for rechecking. Model 1 in Figure A.1 provides a brief summary of this type of design, and the key features are typically those described below.

1. A reference laboratory that is capable of providing a metrologically traceable assigned value with sufficiently small measurement uncertainty and reliability for the proficiency test item is used. For categorical or ordinal properties, the assigned value should be determined by consensus of experts or other authoritative source. It may be necessary for the proficiency test item to be checked at specific stages during the conduct of the proficiency testing scheme, in order to ensure that there is no significant change in the assigned value.

2. The individual measurement results are compared with the assigned value established by the reference laboratory. The coordinator should take into account the claimed measurement uncertainty of each participant, or the claimed level of expertise. It may be difficult to compare results on a group basis as there may be relatively few participants having measurement capabilities that closely match each other.

3. Schemes involving sequential participation take time (in some cases, years) to complete. This causes a number of difficulties, such as

• ensuring the stability of the item,

• the strict monitoring of the circulation among participants and the time allowed for measurement by individual participants, and

• the need to supply feedback on individual performance during the scheme's implementation, rather than waiting until it finishes.

4. Proficiency test items (measurement artefacts) used in this type of proficiency test can include, for example, measurement reference standards (e.g. resistors, micrometers and frequency counters) or, in medical programmes, histology slides with confirmed diagnoses.

5. Schemes that follow this design but that are limited to situations where a single participant is tested independently are often called “measurement audits”.

6. In some situations, the assigned value for a proficiency test item may be determined by consensus, after all participants (or in some situations, a subset of participants) have completed the measurement comparison.

A.3 Simultaneous participation schemes

A.3.1 General

Simultaneous participation proficiency testing schemes usually involve randomly selected sub-samples from a source of material being distributed simultaneously to participants for concurrent testing. In some schemes, participants are required to take samples, which are then considered to be the proficiency test items for analysis. After completion of the testing, the results are returned to the proficiency testing provider and compared with the assigned value(s) to give an indication of the performance of the individual participants and the group as a whole. Examples of proficiency test items used in this type of scheme include food, body fluids, agricultural products, water, soils, minerals and other environmental materials. In some cases, separate portions of previously established reference materials are circulated. Advice or educational comments are typically part of the report returned to participants by the proficiency testing provider with the aim of promoting improvement in performance. Model 2 in Figure A.1 represents typical proficiency testing schemes of this type, usually for testing laboratories. Model 3 presents a type of scheme that is frequently used in conjunction with simultaneous proficiency testing schemes, for oversight or educational purposes.

As discussed in Annex B, assigned values for these proficiency testing schemes may be determined in a variety of ways. However, either evaluations of performance are based on consensus values from participants (all participants, or a subset of “experts”) or evaluations can be on the basis of independently-determined assigned values.

Known value schemes use assigned values that are determined independently of the participants and involve preparation of proficiency test items with a number of known measurands or characteristics. Certified reference materials can also be used in these schemes, as their certified value and measurement uncertainty can be used directly. A direct comparison can also be made between a proficiency test item and a certified reference material under repeatability conditions. However, care should be taken to ensure that the certified reference material is closely comparable with a proficiency test item. Proficiency test items from previous proficiency testing rounds may be used in this type of scheme, if the item has demonstrated stability.

One special application of proficiency testing, often called “blind” proficiency testing, is where the proficiency test item is indistinguishable from normal customer items or samples received by the laboratory. This type of proficiency testing can be difficult, since it requires coordination with a normal laboratory customer. In addition, because of unique packaging and shipping needs, bulk processing is usually not feasible and homogeneity testing is difficult.

A.3.2 Split-level designs

A common design for proficiency testing is the “split-level” design, where similar (but not identical) levels of measurand are included in two separate proficiency test items. This design is used to estimate the participant's precision at a specific level of a measurand. It avoids problems associated with replicate measurements on the same proficiency test item, or with the inclusion of two identical proficiency test items in the same proficiency testing round.