SIST-TS CEN/TS 17385:2020

SLOVENSKI STANDARD
SIST-TS CEN/TS 17385:2020
01-januar-2020
Metoda za oceno stanja nepremičnin
Method for condition assessment of immobile constructed assets
Condition-Assessment-Verfahren
Méthode pour l’évaluation de l’état des biens immeubles construits
Ta slovenski standard je istoveten z: CEN/TS 17385:2019
ICS:
03.100.01 Organizacija in vodenje Company organization and
podjetja na splošno management in general
91.040.01 Stavbe na splošno Buildings in general
SIST-TS CEN/TS 17385:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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CEN/TS 17385
TECHNICAL SPECIFICATION

SPÉCIFICATION TECHNIQUE

November 2019
TECHNISCHE SPEZIFIKATION
ICS 03.100.01
English Version

Method for condition assessment of
immobile constructed assets
Méthode pour l'évaluation de l'état des biens Condition-Assessment-Verfahren
immeubles construits
This Technical Specification (CEN/TS) was approved by CEN on 19 August 2019 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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 NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 17385:2019 E
worldwide for CEN national Members.

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Contents Page
European foreword . 3
Introduction . 3
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 6
4 Condition assessment overview . 9
Annex A (normative) Guidance on defining a list of defects . 15
Annex B (normative) Method for calculation of aggregated condition class . 17
Annex C (informative) Example of defining a breakdown structure and coding . 19
Annex D (informative) Prioritization and quantifying risks . 22
Bibliography . 26
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European foreword
This document (CEN/TS 17385:2019) has been prepared by Technical Committee CEN/TC 319
“Maintenance”, the secretariat of which is held by UNI.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to announce this Technical Specification: 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.
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Introduction
The condition of an immobile constructed asset is one of the factors which determine the value of the
asset. The asset value is also influenced by the quality of the maintenance performed. As maintenance
costs are a significant part of the total cost of ownership of a constructed asset, maintenance actions will
be carefully weighed against their benefit.
The method in this standard provides an objective evaluation of the physical condition of an asset and is
based on that by NEN for the Dutch market in 2006 and may be used to identify and justify a maintenance
plan for the asset.
Condition assessment can be applied to all immobile constructed assets, including infrastructure assets
such as buildings and bridges. However, this method is less suitable for assets such as electrical and
mechanical equipment. It offers a specific survey methodology to evaluate and record defects, which can
be ascertained by any means necessary.
A condition assessment is based on non-destructive surveys to identify quantitative and qualitative
aspects of defects in an item and hence determine its condition class. Dismantling, sampling and drilling
inspection holes can be included in the assessment. The condition class shall deliver fact-based data to
managers, whom should be enabled to distinguish between medium- and long-term maintenance
measures in relationship to the desired level of maintenance. Alternative maintenance scenarios can thus
be developed and evaluated against the value of the asset, which in turn may lead to a change in asset
management policy.
A condition assessment has an explicit technical approach and is one of many influential aspects playing
a role in supporting property management. Aspects like safety, compliance with legislation, quality of use,
social quality, location, flexibility, breakdown risks may play a significant role too, but are all excluded
from the scope of this Technical Specification. Condition assessment is just one aspect for evaluating and
supporting organization policy. The organization policy therefore defines how and where the condition
class is relevant within the set maintenance plans.
This document has the following objectives:
• to deliver uniformity in the condition assessment of assets, systems and elements, expressed by a
condition class. The condition class is a measure of the degradation of the asset and a rating based
on objectively registered defects;
• to deliver unity and insight into the sorts of defects. Each defect is weighted against the parameters
severity, level of degradation and extent;
• to deliver fact-based input data to enable a priority proposition for maintenance action when
weighted against all relevant aspects;
• to deliver a method to set out maintenance plans and evaluating the functioning of maintenance
management on different organization levels.
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1 Scope
This document describes a method to assess the physical condition of all types of immobile constructed
assets in a uniform and objective way. The assessment results in a condition class, which expresses the
technical state of maintenance of an asset at any certain moment in time on a six-point scale. It therefore
can represent either the deterioration of an asset or part thereof or the physical condition at the time of
commissioning. By repeating the assessment at regular intervals, it is possible to monitor the degradation
of the asset over time.
This document offers a uniform, objective and reproducible method with traceable results. It describes
how to achieve the condition class, based on non-destructive observation of defects off any asset or part
thereof by using a predefined breakdown structure. The appropriate breakdown structure of an asset is
dependent upon the asset concerned and guidance for defining a uniform breakdown structure is given
in Annex C.


Figure 1 — Applicability of condition assessment
This document as part of an Asset Management plan can be applied to:
a) evaluate the actual physical condition of a single asset or portfolio of assets;
b) establish a maintenance strategy based on the actual condition of the assets;
c) support financial planning;
d) encourage and support communication about the actual condition versus the desired condition.
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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 https://www.iso.org/obp
3.1
asset owner
any organization or representative thereof that is legally entitled party of an asset portfolio
3.2
breakdown structure
hierarchical decomposition of an asset for assessment purposes
Note 1 to entry: The asset breakdown structure is defined so as to enable assessment and recording of results to be
performed for logical and easily identified elements.
3.3
component
constituent part of a system which cannot be physically divided into smaller parts without losing its
particular function
[SOURCE: IEV 151-11-21, modified – Word "device" replaced by "system"]
3.4
condition
physical state of an object at a particular time compared to the time of commissioning
[SOURCE: EN 16096:2012, 3.1, modified]
3.5
condition assessment
objective method for determining the physical condition of a constructed asset or a part of it
Note 1 to entry: The condition assessment is based on a survey of defects. In specifying the condition class, three
defect parameters are used; severity, level of degradation and extent.
3.6
condition class
categorisation of item condition at a defined point in time
Note 1 to entry: Condition class is the result of three parameters of the defect(s): severity, level of degradation and
extent.
Note 2 to entry: An identified level of degradation may continue to deteriorate or remain stable with time.
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3.7
condition survey
activity, performed either manually or automatically, intended to measure the characteristics and
parameters of the physical actual state of an item
3.8
correction factor
formula which gives the weight of influence according the components in relation with a subsystem
3.9
defect
any degradation of the part compared to the physical condition at the time of commissioning
Note 1 to entry: The definition is different to the one given in ISO 9000
3.10
degradation
detrimental change in physical condition of an item
Note 1 to entry: Degradation may lead to a failure.
Note 2 to entry: Degradation considers also changes in the appearance.
Note 3 to entry: Detrimental change is associated with age, use or external causes on an item and may be progressive
or static.
3.11
element
level of sub-division of an item hierarchy of which condition is to be assessed
Note 1 to entry: An item hierarchy is generally defined with the view of achieving a given objective, for example by
performing a definite function.
Note 2 to entry: Components of an item hierarchy may be natural or man-made material objects, as well as modes
of thinking and the results thereof (for example forms of organization, mathematical methods and programming
languages).
Note 3 to entry: The item hierarchy is considered to be separated from the environment and the other external
systems by an imaginary surface which cuts the links between them and the system.
Note 4 to entry: The term “item hierarchy” should be qualified when it is not clear from the context to what it refers,
for example control item hierarchy, calorimetric item hierarchy, item hierarchy of units, transmission item
hierarchy.”
3.12
extent of defect
fraction affected by the defect in relation to the full element
Note 1 to entry: The extent may be expressed as a physical fraction of the element under assessment or as the
fraction of the element value compared to that at commissioning.
3.13
immobile constructed asset
item that is constructed or results from construction operations that during its primary use for its
functioning is directly or indirectly fixed to the ground
EXAMPLE Railways are included, train is excluded
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3.14
indenture level
level of sub-division within an item hierarchy
EXAMPLE Bridge, superstructure, deck, deck beam.
Note 1 to entry: From the maintenance perspective, the indenture level depends on the complexity of the item's
construction, the accessibility of sub items, skill level of maintenance personnel, test equipment facilities, and safety
considerations.
[SOURCE: EN 13306:2017, 3.7, modified – Examples are tailored to the scope of this standard.]
3.15
item
part, component, device, subsystem, functional unit, equipment or system that can be individually
described and considered
Note 1 to entry: A number of items e.g. a population of items, or a sample, may itself be considered as an item.
Note 2 to entry: An item may consist of hardware, software or both.
Note 3 to entry: Software consists of programs, procedures, rules, documentation and data of an information
processing system.
[SOURCE: EN 13306:2017, 3.1]
3.16
level of degradation
degree of degradation associated with the defect
3.17
maintenance
combination of all technical, administrative and managerial actions during the life cycle of an item
intended to retain it in, or restore it to, a state in which it can perform the required function
Note 1 to entry: Technical maintenance actions include observation and analyses of the item state (e.g. inspection,
monitoring, testing, diagnosis, prognosis, etc.) and active maintenance actions (e.g. repair, refurbishment).
[SOURCE: EN 13306:2017, 2.1]
3.18
maintenance plan
structured and documented set of tasks that include the activities, procedures, resources and the time
scale required to carry out maintenance
[SOURCE: EN 13306:2017, 2.5]
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3.19
severity
potential or actual detrimental consequences of a failure or a fault
Note 1 to entry: The severity of a failure may be related to safety, availability, costs, quality, environment, etc.
[SOURCE: EN 13306:2017, 5.14]
3.20
system
set of interrelated components considered in a defined context as a whole and separated from their
environment
[SOURCE: 151-11-27, IEV 351-42-08, modified – Notes to entry deleted]
4 Condition assessment overview
4.1 General
The assessment methodology described in this document is a structured process intended to provide a
consistent and repeatable evaluation of the condition of an immobile constructed asset. The condition
assessment should be performed according to the requirements of a defined agreement between the
asset owner and the condition assessor or assessing organization. This will normally include the
objectives of the assessment with respect to identification of required maintenance or other actions.
The condition assessment should include the following stages:
a) Establish the asset boundaries and identify the asset breakdown structure and indenture levels;
b) Visual and physical surveys to quantify defects and classify defects;
c) Determination of the condition class(es) by interpretation and combination of the identified defects
and their classification;
d) Report assessment results.
Each stage is described in the following clauses.
4.2 Identification of asset boundaries and breakdown structure of the asset
4.2.1 General
The condition assessment is based on a survey of the elements of an asset. The definition and
documentation of elements for survey is performed in three stages:
a) Identification of the boundaries of the asset to be assessed;
b) Definition of asset breakdown structure;
c) Description of the elements to be assessed and their material(s).
The number of indenture levels in the asset breakdown structure will depend on the size and complexity
of the asset. The lowest level in the hierarchy should be the elements which are to be assessed.
NOTE All elements are associated with materials; it is these materials to which defects are related.
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4.2.2 Identification of asset boundaries
The subject of the assessment and its boundaries should be described to ensure that the scope of the
assessment is understood by both the users of the results and the assessor(s), so that important aspects
are not omitted due to incorrect assumptions concerning the scope. This description may include
diagrams, functional-hierarchy structure diagrams, or reference to documents where such information
can be found.
The boundaries, relationships, dependencies and interfaces between the subject of the assessment and
other parts of the system or environment should be delineated.
Where possible, boundaries should be defined to facilitate each assessment and its integration with other
related studies.
In some cases, it might be useful to define boundaries from a functional viewpoint to limit the number of
links to other items within the scope of a specific assessment. This is often the case if the item is complex
with multiple interfaces within or across boundaries.
4.2.3 Definition of asset breakdown structure
For large or complex assets it might be necessary to sub-divide the asset into a suitable hierarchy of
subsystems, or groups, for each element of which an assessment is performed. This process of
decomposition results in an ‘Asset Breakdown Structure’. The structure may be defined along physical or
functional boundaries, and might be influenced by contractual requirements or organizational factors.
The sub-division should be selected so that the size of each element assessment is manageable and is
logically connected to others.
Special attention should be paid to the interfaces between the subsystems and elements so that the
boundaries within which they fall can be clearly defined.
Where the asset is sub-divided, it should be performed in such a manner that:
a) the elements have clear functional or logical boundaries;
b) individual interfaces can be identified between the elements or between an element and the
environment;
c) a meaningful assessment can be performed.
In performing the sub-division, account should be taken of the purpose for which the assessment is
undertaken and the ability to perform remedial actions if required. Assessment is of little value if the
organization has not authority or resources to undertake the identified actions.
4.2.4 Description of the elements
A clear and unambiguous description of the element should be provided together with a reference code
to aid identification.
The reference code should identify the element and, whenever possible, its constituent materials with
reference to the item to which it belongs. The code should be allocated to each element such that it:
a) is unique, in order to ensure the traceability of the information;
b) is maintenance oriented rather than construction oriented;
c) gives information about the function of the item to which the element belongs and not only its
physical structure.
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EXAMPLE A roof is considered by an architect to be a single system, but for the maintenance process it may
be split into three main components: waterproofing, thermal insulation and structure.
Further guidance on sub-division and coding is given in Annex B.
4.3 Survey with qualitative and quantitative analysis of defects
4.3.1 General
Condition assessment is based on the ability to identify and quantify defects. The identified elements are
surveyed to document the observable defects and each defect classified by three condition parameters:
the severity, the level of degradation and the extent of the defect.
To enable consistency in interpretation of the condition parameters, a framework for classification is
defined in the following clauses. Having assigned the appropriate condition parameters to the element,
an overall condition class can be assigned using the matrix in Table 4.
NOTE A standard list of defects is not included in this document.
4.3.2 Level of detail of a condition assessment
Defects are at the heart of the condition assessment described in this document. An important part of the
methodology described here is objectivity when detecting and assessing defects. This ensures that
condition classes can be compared. To be able to compare condition classes another aspect is vital: level
of detail of the condition assessment; or in other words the way in which defects and their parameters
are detected.
When one surveyor detects defects by performing a non-destructive physical and another uses specific
instruments the way in which they will determine the condition class will be the same, but the latter will
be able to detect defects and/or parameters of defects that the first one cannot. This will result in a
different condition class and will make the results of both surveys incomparable.
The methodology described in this document does not exclude any level of detail for a condition
assessment (i.e. any way in which defects or parameters (severity, level of degradation, extent) can be
detected (either visually, by using a sensor or with use of measuring instruments). But to be able to
compare results of a condition assessment (i.e. condition classes) the same level of detail should be
applied.
4.3.3 Defect severity
The defect severity is related to its influence on the functioning of the element and classified into three
levels: critical, serious and minor defects.
The classification of the severity is determined using Table 1.
Table 1 — Severity classes
Severity Description Example
Minor Does not affect the functionality of the These are mostly aesthetic defects, e.g.
defects element directly scratches, or dirt deposits
Serious Influences the secondary function of an Weathering of paint does not directly
defects element, which will lead to impact on the influence the strength of a window frame,
primary function but will finally lead to wood rot
Critical Influences the primary function of the Wood rot in the corner of a window frame
defects element has direct influence on the strength of this
frame.
A detailed clarification of the severity classification can be found in Annex A.
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4.3.4 Level of degradation
The level of degradation associated with a defect is expressed in terms of the visible detrimental change
in physical condition, with time, use or external cause. Thus the degradation may be progressive or as a
result of a single event.
XAMPLE An area may be subject to corrosion due to continued exposure to water which will
E
progress with time. Alternatively, a surface may be cracked as a result of an impact.
The level of degradation is classified as shown in Table 2.
NOTE The classification relates to the condition as observed and does not evaluate the potential for further
degradation.
Table 2 — Levels of degradation
Degradation Designation Description
levels
Level 1 Low The degradation is hardly discernible /
superficial
Level 2 Medium The degradation is clearly discernible /
significant
Level 3 High The degradation is severe
4.3.5 Extent
The extent of a defect may be assessed according to the area or volume of the element affected. The extent
is then classified according to the percentage of the total element area or volume. The classification is
thus the same for many small occurrences of a defect on an element and a single larger occurrence
affecting the same total area or volume. The five classes used are shown in Table 3.
Table 3 — Extent of defect classification
Extent classes Description of class Percentage extent
Class 1 Extent of defect is minimal ≤ 2 %
Class 2 Extent of defect is insubstantial > 2 %, ≤ 10 %
Class 3 Extent of defect is substantial > 10 %, ≤ 30 %
Class 4 Extent of defect is significant > 30 %, ≤ 70 %
Class 5 Defect is widespread > 70 %
NOTE  The percentage of the extent is the same for many small occurrences of a
defect and a single larger occurrence of the same area or volume.
4.4 Condition classes
4.4.1 Determination of the condition class
The condition class of an element is determined by the combination of severity, level of and extent of
degradation as shown in Table 4.
Table 4 should only be used for elements with a single defect type. Where elements have more than one
defect type the procedure described in Clause 4.4.8 should be applied.
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Table 4 — Condition classes
Extent
Degradation Class 1: Class 2: Class 3: Class 4: Class 5:
Severity
level Widespread
Minimal Insubstantial Substantial Significant
(>70 %)
(≤2 %) (>2 %, ≤ 10 % (>10 %, ≤ (>30 %, ≤
) 30 %) 70 %)
1: Low 1 1 1 1 2
Minor
2: Medium 1 1 1 2 3
defects
3: High 1 1 2 3 4
1: Low 1 1 1 2 3
Serious
2: Medium 1 1 2 3 4
defects
3: High 1 2 3 4 5
1: Low 1 1 2 3 4
Critical
2: Medium 1 2 3 4 5
defects
3: High 2 3 4 5 6
4.4.2 Condition class 1 (excellent condition)
No or very limited degradation. Element defects do not or only rarely occur. Operational interruptions as
a result of systems breakdown etc., do not occur. Defects in the form of slight mechanical damage or of an
aesthetic nature may be encountered occasionally. In the overall view of defects, elements are in an
excellent state, professionally executed.
4.4.3 Condition class 2 (good condition)
Initial degradation. Element defects in the form of material damage and degradation of finishing, material,
components and construction occasionally occur. Defects, such as signs of weathering, are only noted in
places. The elements are of good quality with regard to the total defect impact. This accompanies good
design, good detailing, as well as a professional execution and fitting.
4.4.4 Condition class 3 (fair condition)
The degradation is identifiable in places. Elements have defects in finish, material and components in
places. Elements may occasionally be degraded without critical consequences. Well-executed and long-
lasting repairs may be regularly undertaken. Repairs using less suitable means may also have been
carried out in places. The technical state is qualified as reasonable with respect to the total defect impact.
The quality of the materials applied and/or defects in design, detailing and execution play a significant
role in this.
4.4.5 Condition class 4 (poor condition)
The degradation is widespread. Elements have widespread defects in finish and function. There may be
a number of (severe) defects that can lead to a loss of function. Reliability is compromised. With regard
to the total defect impact, the elements are evaluated as degraded. This may be partly caused by faults in
material choice, poor basic quality, execution and ageing.
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4.4.6 Condition class 5 (bad condition)
The degradation is serious. Components have significant defects in finish and function. Reliability has
reached a critical stage. The general defect impact for the elements is bad. The cause is structural defects,
advanced or premature signs of ageing, or poor execution.
4.4.7 Condition class 6 (very bad condition)
The degradation is advanced and affects nearly all elements. The elements are unusable and technically
ready for demolition.
4.4.8 Aggregation of condition classifications
When more than one defect type has been identified in an element, one of the following approaches can
be applied to de
...