CEN/TS 14773:2004

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Loss as a quality of service indicator
  4.1 General
  4.2 Calculation and presentation of loss and
      substantial delay
      4.2.1 General
      4.2.2 Period after which an item is considered
            to be lost or substantially delayed
      4.2.3 Service performance indicator
5 Methodology
  5.1 General
  5.2 Estimators
      5.2.1 General
      5.2.2 Accuracy
      5.2.3 Measurement results
      5.2.4 Calculation of the accuracy
      5.2.5 Aggregation of results
  5.3 Validation and control of panellist information
      5.3.1 General
      5.3.2 Panellist requirements
      5.3.3 Validation of information
  5.4 Treatment of clusters of lost items
6 Test mail characteristics
7 Report
8 Quality control and auditing
Annex A (normative) Calculation of the accuracy of the
        estimator of the performance indicator
Annex B (normative) Panellist management and validation
  B.1 Management, guidance, training and monitoring of
      panellists
  B.2 Item validation
  B.3 Panellists validation
Annex C (normative) Quality control and auditing
  C.1 General
  C.2 Sending test items
  C.3 Receiving test items
Annex D (informative) Use of different rules for defining
        substantial delay
  D.1 General
  D.2 Circumstances when additional analysis is appropriate
  D.3 Reporting requirements for additional analyses
Annex E (informative) Experience of measuring loss
  E.1 General
  E.2 Experience in Portugal
      E.2.1 General
      E.2.2 Brief description of the Portuguese system
  E.3 Experience in United Kingdom
  E.4 Experience in Germany
  E.5 Comments from International Post Corporation
      E.5.1 General
      E.5.2 Response Rates (Referring to requirements under
            5.3)
      E.5.3 Clustering (Referring to requirements under 5.4)
      E.5.4 Sample sizes (Referring to Annex A)
      E.5.5 Matching reality
  E.6 Comments from France
      E.6.1 General
      E.6.2 Panel efficiency rate
      E.6.3 Confirmation procedures
  E.7 Concluding Remarks
Bibliography

This document specifies methods for measuring the level of loss and substantial delay, using a survey of test letters, of domestic and cross-border priority and first class single piece letter mail, collected, processed and distributed by postal service operators.It is impossible in practice to distinguish between items which will never arrive and items which have been delayed for a very long time. A minimum period is therefore defined after which an item that has been sent shall be treated as if it has been lost or substantially delayed for the purposes of measurement.The resulting overall figure for loss and substantial delay is to be expressed as a percentage of the total posted priority and first class single piece mail. This indicator does not measure the postal operator's overall performance in a way which provides direct comparison of postal service operators, and does not include other service performance indicators other than those related to loss and substantial delay.According to this document, loss and substantial delay is estimated within specified accuracy limits. When the level of loss is very small it may only be possible to estimate an upper limit for the level of loss.This document has been developed from and is compatible with the requirements of EN 13850 for the measurement of the transit time of end-to-end services for single piece priority mail and first class mail, so that the same survey may be used to measure loss and substantial delay and on-time performance. Thus it comprises a set of requirements for the design of a measuring system involving the selection and distribution of test letters sent and received by selected panellists, according to a specification that ensures that the test letter sample design is representative of the real mail flows.