EN 13850:2020

SLOVENSKI STANDARD
01-oktober-2020
Nadomešča:
SIST EN 13850:2013
Poštne storitve - Kakovost storitev - Merjenje časa prenosa od sprejema do
vročitve za posamične pošiljke prednostne pošte in pošte prvega razreda
Postal services - Quality of services - Measurement of the transit time of end-to-end
services for single piece priority mail and first class mail
Postalische Dienstleistungen - Dienstqualität - Messung der Durchlaufzeit von
Einzelbriefsendungen mit Vorrang und Einzelbriefsendungen erster Klasse von Ende zu
Ende
Services postaux - Qualité de service - Mesure du délai d'acheminement des services de
bout en bout pour le courrier prioritaire égrené et de première classe
Ta slovenski standard je istoveten z: EN 13850:2020
ICS:
03.120.99 Drugi standardi v zvezi s Other standards related to
kakovostjo quality
03.240 Poštne storitve Postal services
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13850
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2020
EUROPÄISCHE NORM
ICS 03.240
English Version
Postal services - Quality of services - Measurement of the
transit time of end-to-end services for single piece priority
mail and first class mail
Services postaux - Qualité de service - Mesure du délai Postalische Dienstleistungen - Dienstqualität - Messung
d'acheminement des services de bout en bout pour le der Durchlaufzeit von Einzelbriefsendungen mit
courrier prioritaire égrené et de première classe Vorrang und Einzelbriefsendungen erster Klasse von
Ende zu Ende
This European Standard was approved by CEN on 27 April 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13850:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 14
5 Transit time as a Quality-of-Service indicator . 15
6 Methodology . 17
7 Report . 25
8 Quality control and auditing . 29
9 The annexes . 30
Annex A (normative) Accuracy calculation . 31
Annex B (normative) Transit Time Calculation Rule . 41
Annex C (normative) Quality control and auditing . 49
Annex D (normative) Relaxation related to flows with small real mail volumes . 53
Annex E (informative) Purpose of postal Quality of Service standards. 57
Annex F (informative) Considerations before implementing EN 13850 . 59
Annex G (informative) Design basis . 67
Annex H (informative) Implementing EN 13850 . 76
Annex I (informative) Application of the accuracy calculation . 104
Bibliography . 116

European foreword
This document (EN 13850:2020) has been prepared by Technical Committee CEN/TC 331 “Postal services”,
the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2020, and conflicting national standards shall be
withdrawn at the latest by December 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN shall not be held responsible for identifying any or all such patent rights.
The changes to the 2012 version are limited and concern editorial improvements and the correction of small
errors. Without giving a complete overview, these points can be mentioned:
• Definitions have been aligned with other ISO standards (accuracy 3.1, characteristic 3.7, estimator
3.27, inspection 3.32)
• The definition of panellist has been added (3.39)
• The maximum number of test letters per week per panellist has been explained in more detail in
chapter 6.2.1
• “Zone” has been changed to “area”
• The independence of the auditor to the measurement has been further highlighted in chapter 8
• The formula in the note concerning Table A1 has been corrected
• In Annex H the issue of the handling by customs has been referred to
• Annex J (changes to the 2007 version) has been deleted
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association (Standardization request M/548), and supports essential requirements of
EU Directive(s).
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Introduction
General
The European Commission emphasises the need to have common rules for the development of community
postal services and the improvement of Quality-of-Service (QoS). The Commission has identified
requirements for postal QoS-Measurement systems that include:
 Independent end-to-end measurement capabilities;
 A focus on national and cross-border distribution service performance;
 A single, uniform and reliable system for monitoring distribution service performance within the Union.
The Commission has acknowledged that the different postal traditions and cultures in Europe would not
allow for the establishment of one common unified European measurement system and that national
systems should have sufficient freedom to reflect national needs and peculiarities. On the other hand, they
should fulfil a defined set of minimum requirements to satisfy the information interests of the European
Commission, the regulatory authority, postal customers and postal operators themselves. Any regulatory
authority is free to adapt to national circumstances where the standard gives room to do so. This is
explained further in Annex E.
The objective of the measurement is to estimate the end-to-end transit time QoS given to the customer
domestically in each European country and cross-border between the European countries. This European
Standard refers to a number of principles and minimum requirements to be applied for the measurement of
the end-to-end transit time service level.
Regulatory background
The regulatory basis of EN 13850 is laid out in the 97/67/EC, as amended by Directive 2002/39/EC and
Directive 2008/6/EC.
Main guidance is given in Chapter 6 Quality of Service. Article 16 states: “Member States shall ensure that
quality-of-service standards are set and published in relation to Universal Service in order to guarantee a
postal service of good quality”.
Furthermore, EN 13850 is mandatory for measuring the performance levels of single piece priority or first
class mail which falls under the universal service .
For intra-community cross-border mail of the fastest standard category a minimum QoS level is laid down in
the Directive 97/67/EC. At least 85 % of all letters shall have an end-to-end transit time of J+3 and less and
at least 97 % of all letters shall have an end-to-end transit-time of J+5 and less.
The mandate for this revised version of EN 13850:2020 is the Standardization request (M/548) of the
European Commission which asked CEN/TC 331 to “revise existing standards" and to cover the topic "a
method for transit time measurement for cross border postal items" in order to satisfy regulatory needs.

See also: “Letter to all Members of the Postal Directive Committee, 21.03.2005, Brussels, Markt/E4/JR/DS/HM D(2005) –

2346” (N676, CEN/TC331)
See also: “Postal Directive 97/67/EC: Article 18.1 and Annex” and “Postal Directive 2008/6/EC: Article 18.1 and Annex 2,

Article 1”
1 Scope
This document specifies methods for measuring the end-to-end transit time of domestic and cross-border
Single Piece Priority Mail (SPPM), collected, processed and delivered by postal service operators. It
considers methods using representative end-to-end samples for all types of single piece priority mail
services for addressed mail with defined transit-time service levels offered to the customer. This document
is applicable to the measurement of End-to-End priority mail services.
The standardised QoS-measurement method provides a uniform way for measuring the end-to-end transit
time of postal items. Using a standardised measurement method will assure that the measurement will be
done in an objective and equal way for all operators in accordance with the requirements of the Directive
97/67/EC and its amendments.
It is not the purpose of this document to measure the postal operators’ overall performance in a way that
provides direct comparison of postal service providers.
This document relates to the measurement of the SPPM services given to household and business customers
that post mail at street letterboxes, over the counter at post offices or have pick-ups at their offices. To cover
flows with smaller mail volumes this document includes flexibility areas for adapted implementation. For
technical reasons this document may not be suitable for the measurement of very small volumes of mail.
The end-to-end service measured may be provided by one operator or by a group of operators working
either together in the same distribution chain or parallel in different distribution chains. This document is
not applicable for the measurement of end-to-end transit times in fields of study with more than one
induction operator (Multi-Operator Environments), which require different methodologies. The method for
end-to-end measurement specified in this document is also not designed to provide results for the
measurement of parts of the distribution chain.
This document is not applicable for the measurement of end-to-end transit times of bulk mailers’ services
and hybrid mail, which require different measurement systems and methodologies (see, for example, EN
14534 Measurement of the transit time of end-to-end services of bulk mail).
This document includes specifications for the quality control and auditing of the measurement system.
This document does not specify:
 the minimum acceptable level of accuracy that will be required by the national regulatory authority;
 the target(s) that the regulatory authority might set;
 how the regulatory authority should determine whether the target(s) have been met.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
accuracy
closeness of agreement between a test result or measurement result and the true value
Note 1 to entry: The term accuracy, when applied to a set of test results, involves a combination of random
components and a common systematic error or bias component.
[SOURCE: ISO 3534-2:2006]
Note 2 to entry: In this standard the accuracy is expressed as ±ε, where 2ε is the length of the confidence interval at the
confidence level 95 % for the parameter being estimated, namely the probability of attaining the transit time target.
3.2
aggregation
compounding of primary data into an aggregate for the purpose of expressing them in a summary form
3.3
audit
systematic and independent examination to determine whether activities and related results comply with
planned arrangements and whether these arrangements are implemented effectively and are suitable to
achieve objectives
Note 1 to entry: The organisation carrying out the audit is called the auditor.
Note 2 to entry: A (full) audit may be carried out as an initial audit of a new or substantially changed system or as an
initial audit by a new auditor. It may also be carried out as a re-audit of the same system by the same auditor in the next
audit cycle.
Note 3 to entry: If an audit results in objections, then the auditor may require corrective actions until a defined
deadline. A final check of these corrective actions is called corrective audit.
3.4
average (arithmetic mean)
sum of values divided by the number of values
[SOURCE: ISO 3534-1:2006]
3.5
bring service
mail collection or mail delivery service, specifically contracted by the customer
3.6
business panellist
panellist with an address other than a household address such as a company or an organisation
3.7
characteristic
distinguishing feature
Note 1 to entry: The characteristics may either help to identify or differentiate between items of a given population
Note 2 to entry: The characteristics may be either quantitative - by variables, or qualitative - by attributes.
[SOURCE: ISO 3534:2006]
Note 3 to entry: In this standard the population is SPPM items and the characteristics are related to type of senders,
type of receivers, times and types of induction or delivery, physical aspects of test items, franking, etc.
3.8
city
geographically defined area according to national classification systems
3.9
clearance
operation of collecting postal items by a postal service provider
3.10
conformity
fulfilment of specified requirements
3.11
corrective action
action taken to eliminate the causes of an existing non-conformity, defect or other undesirable situation in
order to prevent recurrence
3.12
country
territory of a nation with its own government
3.13
cross-border mail
mail from or to another state or from or to a third country
3.14
customer
natural or legal person purchasing a postal service from a postal operator
3.15
date of delivery
date on which a postal item is delivered to the address or to the addressee
3.16
date of induction (J)
date on which a postal item is posted, provided posting takes place before the last collection of that day
Note 1 to entry: The term date of induction has the same meaning as the term date of deposit in the Directive
97/67/EC.
Note 2 to entry: Last collection refers to the advertised last time for collection (not the actual time).
3.17
date of posting
date on which a postal item is posted (irrespective of whether it is posted before the advertised last
collection of that day)
3.18
delivery point
physical location at which delivery of postal items by a postal operator takes place and where they leave the
operator’s responsibility
3.19
design basis
structure in the field of study for which the design of the measurement is representative. The design basis
should be defined before the start of the measurement
Note 1 to entry: If a design basis other than measured real mail flows is selected, then statements regarding the
representativity of the measurement shall be made in relation to the chosen design basis.
3.20
design factor
ratio of the variance of the estimator of the QoS indicator in the given sample design by the variance of the
estimator in an elementary sample design of the same size. The design factor is always related to a given
sample design and estimator
3.21
discriminant characteristic
characteristic affecting the outcome
Note 1 to entry: In this standard a characteristic is discriminant when the transit time significantly differs according to
the different modes of the characteristic (see 6.4.2).
3.22
distribution
process from collecting mail at collecting points through sorting at the mail centre(s) to the delivery of mail
items to the addressee
3.23
domestic mail
mail items sent and received within one country
3.24
effective sample size
total sample size divided by the design factor
3.25
end-to-end
routing from the access point to the network up to the point of delivery to the addressee
3.26
estimate
value of an estimator obtained as a result of an estimation
3.27
estimator
statistic used in estimation of the parameter
Note 1 to entry: In this European Standard, an estimator is a function of the observed values of test-item transit times
allowing the estimation of the probability of attaining the transit time target.
[SOURCE: ISO 3534-1:2006]
3.28
field of study
total SPPM flow between defined postal areas
Note 1 to entry: Some examples for field of study could be:
 Domestic – one induction operator in one country
 Domestic – one induction operator in one part of a country
 Cross-border – one induction operator on a country-to-country link
 Cross-border – one induction operator to one delivery operator
 Cross-border – one induction operator to a group of delivery operators
 Cross-border – one induction operator to one country
 Cross-border – one country to one delivery operator
 Cross-border – one induction operator to a group of countries
 Cross-border – a group of countries to one delivery operator
 Cross-border – one country to one country
Note 2 to entry: Some mail flows between postal operators may not meet the technical requirements in this standard to
qualify as fields of study, e.g. limited mail volumes (see Annex D).
3.29
geographical coverage
spread of postal services within a pre-defined geographical area
3.30
independent performance monitoring organisation
body charged with the monitoring of the QoS according to the methodology specified in this standard, which
is external to, and having no links of ownership or control with the postal operator thus monitored
3.31
induction
deposition of mail into the postal network
3.32
inspection
conformity evaluation by observation and judgement accompanied as appropriate by measurement, testing
or gauging
[SOURCE: ISO 3534-2:2006]
3.33
last collection time
advertised last time for collection or contracted latest time for collection
Note 1 to entry: This is often not equal to the actual collection time, because from the postal work-organisation point of
view, the collection usually happens some time later than the advertised last collection time (e.g. the collection routing
timetable can only be defined with some tolerance).
3.34
metered mail
mail franked by franking machines
3.35
office of exchange
place where a postal operator accepts cross-border mail from a postal operator of another country and
prepares mail for the transfer to other countries
3.36
on-time performance
proportion of postal items within a given period of time with transit times meeting the specification
3.37
on-time probability
probability of the event that the transit time T of a mail item meets the transit time target t, i.e. does not
exceed the specified number t of days:

3.38
one-Operator field of study
field of study with exactly one induction operator
Note 1 to entry: A one-operator field of study may be defined in a multi-operator postal environment.
Note 2 to entry: End-to-end postal operation in a one-operator field of study may include several postal operators for
processing and / or delivery.
3.39
panellist
person acting as sender and/or receiver of test items
Note 1 to entry: Private panellist is a panellist with a household address
Note 2 to entry: Business panellist is a panellist with an address other than a household address such as a company or
an organisation
Note 3 to entry: Professional panellist is a panellist who is paid to perform specific tasks, usually posting mail
in various pre-defined posting points during a day and posting more frequently than private or business panellists
3.40
pick-up time
published time by which the postal operator commits to ensuring that the day’s post is available in the P.O.
Box for collection
3.41
panel turnover
permanent and active exchange of established panellists with new panellists
3.42
panel rotation
active change in the subset of established panellists, which are chosen for participation in a study, or in their
tasks in the study from one period to the other
3.43
postal area
one of the parts into which a postal operator’s whole territory is divided and which is suitable for
characterising postal distribution peculiarities
3.44
postal catchment area
postal area served by a domestic sorting centre or by an office of exchange for cross border mail outbound or
inbound. Catchment areas may be different for outbound and inbound mail or for different fields of study
3.45
postal item
item addressed in the final form in which it is to be carried by a postal service provider
3.46
postal performance indicator
expression used to characterise the performance of a postal operator
Note 1 to entry: In this European Standard, the performance indicator is derived from postal transit time statistics.
3.47
postal service
services involving the clearance, sorting, transport and delivery of postal items
3.48
priority item, first class item, A-class item
postal item sent with priority as defined nationally
3.49
private panellist
panellist with a household address
3.50
professional panellist
panellist who is paid to perform specific tasks, usually posting mail in various pre-defined posting points
during a day and posting more frequently than private or business panellists
3.51
quality
totality of characteristics of an entity that bear on its ability to satisfy stated and implied needs
3.52
quality assurance
every planned and systematic activities implemented within the quality system and demonstrated as
needed, to provide adequate confidence that an entity will fulfil requirements for quality
3.53
quality control
operational techniques and activities that are used to fulfil requirements for quality
3.54
quality evaluation
systematic examination of the extent to which an entity is capable of fulfilling specified requirements
3.55
real mail flow
number of postal items of a given type on a given link within the postal network
3.56
real mail study
studies on real mail flows or real mail characteristics involving sampling of real mail items
3.57
rural
geographical entity with less than a specified number of inhabitants
Note 1 to entry: In context of this standard, ‘rural’ represents the rest of the field of study apart from urban areas as
defined in 3.69.
3.58
service standard
standard that specifies requirements to be fulfilled by a service, to establish its fitness for purpose
Note 1 to entry: For end-to-end transit time monitoring systems the service standard is the number of qualifying days
within which items should be delivered. This service standard is also called ‘transit time target’.
3.59
single piece mail
postal items posted and distributed via a postal service for which a ‘single piece tariff’ for individual postal
items is set in the general terms and conditions of the postal service provider that receives the payment
Note 1 to entry: Single piece mail may be inducted using different modes of payment as long as the induction of
individual postal items is not restricted.
Note 2 to entry: Excluded are all postal services that contain further requirements on the induction like, for example,
the registration of items, minimum induction volumes, equal contents or a pre-sortation of the inducted mail.
3.60
sorting centre
place where the main sorting of mail is done
3.61
stamped mail
postal items paid for with postage stamps
3.62
stratification
division of a population into mutually exclusive and exhaustive subpopulations (called strata)
Note 1 to entry: A Stratification is thought to be more homogeneous with respect to the characteristics investigated
than the total population
[SOURCE: ISO 3534-2:2006]
3.63
study domain
subpopulations for which separate results may be appropriate
Note 1 to entry: Study domains could be defined for example by geographic segmentation or by product
3.64
test item
postal item produced in the test measurement system for the purpose of measuring transit time Quality-of-
Service.
Note 1 to entry: A test item should be assigned to a stratum in the field of study.
Note 2 to entry: It should be manufactured, inducted and delivered according to the discriminant mail characteristics
defining the stratum
3.65
test period
period under which measurement has been carried out and for which the results are presented in a separate
test report
3.66
time of delivery
time when a postal item is delivered at its delivery point
3.67
time of posting
time when a postal item is posted at its induction point
Note 1 to entry: The time of posting may be before or after the actual last time of collection.
3.68
transit time
number of days elapsed between date of induction and date of delivery of a mail item
Note 1 to entry: The transit time is calculated according to 5.2.3
3.69
urban
geographical entity with not less than a specified number of inhabitants
3.70
user
any natural or legal person benefitting from postal service provision as a sender or an addressee
3.71
weighting
compensation for the difference between the distributions of characteristics in the measurement system
compared to the chosen design basis
4 Symbols and abbreviations
CMW Calculated Mode Weights
df Design factor
DMC Discriminant Mail Characteristic
EC European Commission
ESS Effective Sample Size
EtE End-to-End
IFW Individual Final Weight
IRV Intra Relation Variation
IT Information Technology
J Date of induction
MSS Minimum Sample Size
OLR One Letter Relations
QoS Quality of Service
RMW Real mail Mode-Weights
RMS Real Mail Studies
RSW Real mail Strata-Weights
RtT Relation-to-Total Variation
SPPM Single-Piece Priority Mail
SRS Simple Random Sample
StrRS Stratified Random Sample
StrEtE Stratified End-to-End Sample
SWB Standard Weighting Basis
USO Universal Service Obligation
WB Weighting Basis
5 Transit time as a Quality-of-Service indicator
5.1 General
The overall transit time QoS level is to be expressed as the percentage of mail distributed within J+n days
end-to-end (see the Directive 97/67/EC and its amendments). It specifies a set of requirements for the
design of a QoS measuring system for SPPM, involving the selection and distribution of test items sent and
received by selected panellists. The sample design gives the specifications for the panellists and items to be
representative of the chosen design basis. The design basis is the most appropriate structural information
available to characterise all real mail distributed in the field of study.
The system for measuring the distribution of the end-to-end transit time of SPPM items shall be robust and
shall give a statistical measurement at a defined level of accuracy.
These requirements also consider fields of study that cover flows with small mail volumes. Provisions for
these fields are detailed in Annex D, where the fields of study are categorised in up to four mail-flow classes.
References to higher flexibility in some of these classes are given in several notes throughout this standard.
All measurements shall refer to the end-to-end transit time.
The sample design shall be representative of the chosen design basis. The design basis shall be selected
according to its ability to characterise all real mail distributed in the field of study.
The measuring system shall provide one annual figure for the field of study.
NOTE 1 The figure presented annually may require a test period of 1, 2 or 3 years according to Annex D.
NOTE 2 For cross-border mail flows in categories 2 or 3 of Annex D it will take 2 or 3 years, respectively, to reach the
required minimum sample size.
The measurement methodology shall be objective and shall be auditable.
The field of study shall be used consistently throughout the measurement period.
If the field of study is composed of several study domains, it is the QoS measurement for the overall field,
which shall comply with the requirements of this European Standard.
The group of countries in a cross-border field of study should be used consistently throughout the
measurement period.
5.2 Transit time calculation
5.2.1 Measurement unit
The transit time of a postal item shall be measured in units of days and expressed as J+n days. The day of
induction J is the date of the next collection after posting.
5.2.2 Continuity of measurement
The measurement system shall be continuous. Posting shall cover all months and weeks of the year and at
least all collection days of the week in accordance with the definition of the measurement unit and the
transit-time calculation rule. All periods of the year shall be included as well as Christmas, Easter and
summer holiday periods.
Non-functioning of the postal operator and days of strikes or industrial disputes shall not be discounted.
However, in case of “force majeure” events, deduction of corresponding periods may be considered. Any
deduction shall be indicated in the reporting and be subject to audit.
Any intended deduction shall be reported to the regulatory authority without delay. Agreement with the
regulatory authority on all planned deductions due to force majeure is required prior to the calculation of
the annual report.
For an event to qualify as force majeure, the incident shall fulfil the following minimum requirements. It
shall;
 not be caused by the operators involved in the distribution and / or their subcontractors,
 be unforeseeable and,
 be unavoidable by them.
It shall;
 be a rare event,
 have a provable impact on several consecutive days of distribution.
Thus in case of, for example, natural disaster or terror attacks it should be allowed to consider the deduction
of the corresponding period during which operation is affected in such a way that transit times cannot be
guaranteed by “normal” postal operation.
Test items shall be posted on all seven days of the week. Published days without collection (i.e. non-
collection days made known to the public in advance) may be excluded.
5.2.3 Calculation of the transit time
For the purpose of this European Standard, transit times for domestic and cross-border mail shall be
calculated according to the working week calculation rule as presented in Annex B. Published regional
holidays may be subtracted in the calculation of transit time.
The calculation of the transit time takes into account test items posted before the last collection time of the
day for the type of mail in the field of study. The last collection time is taken as stated on the postal letterbox,
published at the post office or otherwise announced by the postal operator. Test items posted after that time
shall be considered as posted on the next collection day.
If a test item is posted after the last collection time, then the day of induction J should be adjusted to the next
working day for this type of mail. Restricted collections, e.g. later collection times for delivery within a local
area, may be taken into account provided they have been advertised to customers.
It is necessary to ensure that panellists can identify the delivery of the item to the address, or the receipt of
the item to a named individual.
If P.O. Boxes are to be included in the sample, panellists will need to be able to confirm that they collect the
mail daily after the published pick-up time.
If there are items included in the survey which are not letterbox friendly or for some other reason cannot be
delivered without the presence of the panellist, it is the first attempt to deliver that should count as the date
of delivery if the date of the first attempt to deliver can be retrieved from a written notification.
Only valid test mail items shall be included in the calculations.
5.3 Service performance indicators
The following indicators shall be used in the presentation of the transit-time service level result. Only valid
test mail items shall be included in the calculations. All postal items delivered up to J+30 shall be considered
in the calculations. Postal items not delivered by J+30 may be excluded, because they may be deemed as lost
or are not detectable in the system any more within the reporting period.
 On-time performance: The percentage of postal items delivered within the defined service standard. The
result shall be presented as the percentage of postal items arriving within the transit time J+n, where n
represents the number of qualifying days for the service standard. All reports shall state the level of on-
time performance accuracy achieved in the measurement period.
 Cumulative distribution of delivery days: The cumulative percentage of mail delivered within a given
period from J+1 to J+10 shall be reported.
6 Methodology
6.1 Representative sample design
The study shall be based on a defined methodology.
The methodology shall be based on test mail volumes representative of the chosen design basis. It shall
define indicators that are representative of the transit time QoS provided in the measurement period.
The design basis shall be defined before the start of the measurement. If a design basis other than measured
real mail flows is selected then statements regarding the representativity of the measurement shall be made
in relation to the chosen design basis.
It is common practice to define the design basis as the total system of existing real mail flows in the field of
study (standard design basis). Statements regarding the representativity of the measurement shall be
interpreted in line with the standard design basis if no reference to an alternative design basis is made.
The measurement shall be carried out by an independent performance-monitoring organisation. The test
mail method shall consist of a process in which panellists act as senders and/or receivers. Senders induct
test items into the postal operator’s mail network and register date and time of posting; receivers register
the date of delivery.
Senders and receivers shall be spread over all the field of study based on the panel size and the
corresponding minimum number of postal areas to be covered, in order to fulfil the specifications of
minimum sample size, maximum panellist workload, stratification and geographical coverage. The sending
and receiving process shall be organised in order to fulfil the specifications of the sample design. The test
mail shall be manufactured in order to fulfil the specifications of the discriminant mail characteristics.
A representative sample design may be realised either by a strict proportionality of the test mail flows with
respect to the design basis, or by an over-representation or an under-representation of some strata. The
latter requires corrective weighting, which allows restoring the proportionality.
At least once in every three years or earlier when major changes occur the sample design and weighting
system shall be adjusted.
6.2 Minimum Sample Size (MSS)
6.2.1 Domestic measurement systems
Without calculation, 9 625 items shall be taken as the Minimum Sample Size (MSS) for a domestic
measurement system. With this MSS reliable results can be achieved for all possible performance levels.
The MSS may be reduced, if a performance level better than 50 % can be expected. The MSS then shall be
determined using the following table:
Table 1 — Minimum Sample Sizes for selected performance levels (Domestic)
96,35 92,5 87,5 82,5
95 % 90 % 85 % 80 % 75 % 70 % 65 % 60 % 55 % 50 %
% % % %
1 350 1 850 2 700 3 500 4 250 4 950 5 600 6 200 7 250 8 125 8 800 9 275 9 550 9 625
For any performance level the MSS is the value tabled below the highest performance level still lower than
.
EXAMPLE Let be expected to be 91 %. Then the 90 % is the highest tabled performance still lower than 91 %.
The MSS is then 3500.
This determination of the MSS can be applied for all performance levels from 50 % up to 96,35 % (see also
A.5.2.2). For performance levels of 96,35 % and above at least 1 350 items have to be taken. For performance
levels below 50 % at least 9 625 items have to be taken.
NOTE For fields of study with small mail flows these MSS-requirements are relaxed (see Annex D).
A maximum of 12 letters per week shall be allocated to any domestic sender except business senders with a
mode of payment other than ‘stamped’. A maximum of 24 letters per week shall be allocated to them. A
maximum of 24 letters per week also shall be allocated to the professional panellist for each induction point.
A maximum of 12 letters per week shall be allocated to any domestic receiver. On average, no receiver shall
get more than 6 letters per week during his time of participation in the measurement period.
The given weekly workloads are maximum values. In most cases the actual workloads should be well below
the maximum.
6.2.2 Cross-border measurement systems
Without calculation 386 items shall be taken as the Minimum Sample Size (MSS) for a cross-border
measurement system. With this MSS reliable results be achieved for all possible performance levels.
The MSS may be reduced, if a performance level better than 50 % can be expected. The MSS then shall be
determined using the following table:
Table 2 — Minimum Sample Sizes for selected performance levels (Cross-Border)
97,5 % 95 % 92,5 % 90 % 87,5 % 85 % 82,5 % 80 % 75 % 70 % 65 % 60 % 55 % 50 %
120 148 175 201 226 250 270 290 325 351 370 381 385 386
For any performance level the MSS is the value tabled below the highest performance level still lower than
.
EXAMPLE Let be expected to be 91 %. Then the 90 % is the highest tabled performance still lower than 91 %.
The MSS then is 201.
This determination of the MSS can be applied for all performance levels from 50 % up to 97,5 % (with at
least three non-performing items). For performance levels of 97,5 % and above at least 120 items have to be
taken.
For performance levels below 50 % at least 386 items have to be taken.
NOTE For fields of study with small mail flows these MSS-requirements are relaxed (see Annex D).
A maximum of six letters per week shall be allocated to any cross-border sender, except business senders
with a mode of payment other than ‘stamped’. A maximum of 12 letters per week shall be allocated to them.
A maximum of six letters per week shall be allocated to any cross-border receiver.
The given weekly workloads are maximum values. In most cases the actual workloads should be well below
the maximum.
6.3 Determination of the design basis
6.3.1 General
The design basis may be determined in different ways. The standard design basis is based on real mail flows.
The standard design basis will be determined via a system of real mail studies estimating these flows.
The standard design basis shall be used at least after the first measurement period (see 6.3.3).
Before and during the first measurement period the use of alternative design bases may be necessary.
Different discriminant mail characteristics may have different design bases.
The design basis shall be provided by the stakeholder(s) commissioning the measurement.
The design may be based on estimated real mail volumes in the field of study. The methodology and
reasoning leading to the determination of the design
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