ISO/DIS 15686-2.2:2025(en)

ISO/TC 59/SC 14

Secretariat: BSI

Date: 2025-09-04

Buildings andcivil engineering works—Service life planning— Part 2:Process considerations

© ISO 2025

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Contents

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Foreword vi

Introduction vii

1 Scope viii

2 Normative references 1

3 Terms and definitions 1

4 Service life planning – requirements and design 1

4.1 Design Life Requirements 1

4.2 The design life 2

5 Service Life Predictions and Estimates 3

5.1 Service Life Prediction Processes 3

5.2 Reference service-life data and estimated service life 3

5.2.1 Provision of reference service-life data 3

5.2.2 Data sources 4

5.2.3 Data evaluation 5

5.3 Selection of data 5

5.3.1 General 5

5.3.2 Data sources 7

5.3.3 Rejection of data 7

5.3.4 Similarity of in-use conditions 7

5.3.5 Consideration of data quality 7

5.3.6 Form of data 8

5.4 Service life estimation using the Factor Method 8

5.5 Residual Service Life Estimates 8

6 Service Life Performance Reviews 10

6.1.1 The service life performance review process: summary 10

6.1.2 Information framework for service life reviews 12

6.1.3 Constructed asset hierarchy 12

6.1.4 Types of service life 14

6.1.5 Determining service life 15

6.1.6 Service life metrics 15

6.2 Service life review process in detail 16

6.2.1 Stage 1: Scope and aims of the service life review 16

6.2.2 Stage 2: The constructed asset(s) 16

6.2.3 Stage 3: Service life information 16

6.2.4 Stage 4: Service life factors 16

6.2.5 Stage 5: Service life review 17

6.2.6 Stage 6: Service life review report 17

6.2.7 The principle of proportionality 17

Annex A (informative) Service Life Review Reports 19

A.1 Service life reviews at different stages in the asset life cycle 19

A.1.1 Review types 20

A.1.2 Pre-requisites for service life reviews 20

A.1.3 Parties and Roles in the service life review process 20

A.1.4 Documentation 20

A.2 Service Life Review Report 20

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

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This document was prepared by Technical Committee ISO/TC59, Buildings and civil engineering works, Subcommittee SC 14, Service life planning.

This third edition, together with ISO 15686-1:— and ISO 15686-3:—, cancels and replaces ISO 15686-1:2011, ISO 15686-2:2012, ISO 15686-3:2002, ISO 15686-4:2014, ISO 15686-8:2008, ISO/TS 15686-9:2008 and ISO 15686-10:2010, which have been technically revised.

The main changes are as follows:

— The relationship to the revised text in ISO 15686-1:— and ISO 15686-3:— as well as former parts and retained parts of ISO 15686 is indicated.

— Processes to do with performance audits and reviews, reference service life and estimation, as well as some processes to do with service life prediction are described, although the details of the methodology of these are dealt with in ISO 15686-3:—.This Part covers who is involved in the processes, what is involved in the processes, and when they take place over the lifespan of the building or other constructed assets.

A list of all parts in the ISO 15686 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

Service life planning is a process that seeks to ensure that the service life of a building or other constructed asset will equal or exceed its design life. This document deals with who is involved in the processes of service life planning, what those processes are, and when they are carried out. It should be read in conjunction with the general principles in ISO 15686-1 and methods and communication in ISO 15686-3. ISO 15686-5 describes the Life cycle costing process; ISO 15686-7 focuses on the process related to performance evaluation for feedback from service life data from practice.

This document is intended primarily, but not exclusively, for the following user groups, who are also the primary actors in the processes described:

a) building or civil engineering owners and users;

b) design, construction and facilities or asset management teams;

c) manufacturers who provide data on long-term performance of products (and those who provide test data or technical approvals);

d) maintainers of buildings and civil engineering assets;

e) value appraisers of buildings and civil engineering assets;

f) insurers of buildings and civil engineering assets;

g) technical auditors of buildings and civil engineering assets;

h) developers of construction product standards;

i) clients, funders, and sponsors of buildings and civl engineering assets;

j) users of reference service life data as inputs to assessments of sustainability such as environmental product declarations (EPD’s), life cycle assessment (LCA) or life cycle costing (LCC).

k) Regulators of any group listed above.

Service life planning is a group of processes designed to generate an estimate or prediction of how long buildings or other constructed assets and the various parts which comprise them will continue to function satisfactorily, which may include consideration of management interventions to replace or repair some parts to ensure continued functionality and serviceability. Service life planning is generic, i.e. applicable to all types of components of buildings or constructed works, and is meant to serve as a guide to all kinds of prediction processes. The processes can be used to assess innovative components or can be used in the assessment of existing data in order to appraise their value for service life planning and reveal where complementary studies are necessary.

These processes can be undertaken at any stage from early design right through the lifespan. Where they take place during the planning phase of the life cycle of the asset, they comprise an estimate or prediction of projected performance. Where the processes take place during the service life of the asset, they concern the residual service life estimate or prediction of future performance. Depending on the scope of the estimate or prediction, they may include projected performance beyond the life cycle of the works in which the parts are currently embedded.

Because service life planning is concerned with future performance, there are inevitably assumptions made about a future operating conditions, future policies and practice. It is therefore important that it is clear that predictions and estimates are not guarantees or warranties of future performance. Equally it is important that the level of reliance to be placed on the estimate or prediction is clear. Examination of assumptions and the evidence used to form the prediction or estimate may be needed.

Depending on the priorities of the client for the service life planning the focus may be on appropriate design, maintenance, or refurbishment of the building or other constructed assets. The processes may need to take account of changing strategic, operational or policy requirements, risk, reliability or value management aspects, but these are not the primary focus of this document. However, where these considerations affect the estimate or prediction, they should be included in any service life planning reporting.

Buildings and constructed assets—Service life planning— Part 2: Process considerations

This document provides requirements and guidance on the use of service life predictions or reference service-life data and on the application of these data for the purposes of calculating estimated service life using the factor method.. It gives guidelines for the use of evidence on which thereliability of the predicted or estimated service life depends.(see NOTE).

This document establishes when to specify or verify functional performance requirements during the service life of buildings and constructed assets and when to check their capability to meet identified requirements.

This document is applicable to any scope of holdings, whether a set (or portfolio), a single building (large or small) or a facility which is part of a building (such as one group of spaces, one floor or several floors) or part of a network of constructed assets.

It is applicable to the range of roles of stakeholders, from the owners and managers to the occupants, tenants or other users.

This document does not describe specific test methods. It does not cover limitation of service life due to obsolescence.. It does not give guidance on the values of service life factors A to G.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 15686‑1, Buildings and civil engineering works– Service Life Planning – Part 1 Concepts and Principles

ISO 15686‑3, Buildings and civil engineering works – Service Life Planning – Part 3 Methods, data and communication

ISO 15686‑7:2017, Buildings and constructed assets — Service life planning — Part 7: Performance evaluation for feedback of service life data from practice

For the purposes of this document, the terms and definitions given in ISO 6707-1 and in ISO 15686-1 apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp

— IEC Electropedia: available at https://www.electropedia.org/

The basic concept of service life planning is that assets shall reliably meet or exceed required performance for the duration of design life to maintain their intended use and function. In order to achieve this, the following aspects shall be considered:

— Requirements for service life which vary from project to project and from one asset to another depending on intended use and operating environment, and the cost, difficulty, frequency and extent of anticipated maintenance, replacement and repair.

— Very durable, long lasting construction is usually more expensive and canrestrict the design to a limited range of materials. Consequently a long design life requirement may increase the initial cost of the project, though not necessarily the life cycle cost, and may limit the design solutions that meet the brief. Therefore the designer may challenge excessive design life requirements as well as other aspects of the brief, such as the initial budget.

— Financing of construction often presumes a design life at least as long as the period of any loan used to finance the project, which mayt be secured on the project value.

The client shall define the design life of the building or constructed asset in the initial brief, which should reflect the overall requirements – this may entail guidance from designers. The client may also choose to specify the design life for specific assets. This may be undertaken in conjunction with the designer.

Design life categories are given in Table 1 and categories for parts are given in Table 2. These descriptions shall have the following minimum design life requirements unless a specific design life is stated.

Table 1 — Minimum design life requirements

NOTE 1: Specific periods may be determined for particular buildings in any of the categories 2 to 4, provided they do not exceed the period suggested for the next category below in the table, for example prefabricated or industrial buildings may be designed for a design life of 20 years or more.

NOTE 2: Buildings may include replaceable and maintainable components (See Table 2)

Table 2 — Categories of design life for components or assemblies

The design life of an asset shall be determined using available knowledge about the predicted or estimated service life of each component that is to be used in the asset and the proposed operating conditions of the asset.

Where the predicted or estimated service life of any component is less than the design life of the building or constructed asset, a decision shall be agreed with the client as to how performance can be maintained over the life of building or constructed asset (e.g. by replacement or other maintenance) or the design life requirement shall be adjusted to match the actual design life.

Service life planning shall include projections of the needs for, and timing of, maintenance and replacement activities over the life cycle of the building or constructed asset. The person responsible for the service life planning shall assess data on which the projections depend for robustness and reliability, and records of the data sources shall be kept.

As part of design the appropriate performance criteria for the assets shall be identified, together with any data requirements to demonstrate compliance with requirements.

The consequences of failure shall be considered if relevant in determination of design life.

Assets that would present a high risk to health and safety in the event of failure, or those which cannot readily be inspected for degradation, or which are not practically feasible to replace, may require a design life that matches that of the building or other constructed asset.

A predicted service life distribution of a component (PSLDC) shall be determined in accordance with the systematic approach or methodology as described in ISO 15686-3, including consideration of:

— the identification of necessary information;

— the selection or development of test procedures (exposure programmes and evaluation methods);

— testing;

— interpretation of data;

— reporting of results.

The PSLDC shall generally be described by at least two parameters, the expectation value and the standard deviation. However, by agreement with the client, where tests are very costly or time-consuming, a single value predicted service life of a component (PSLC) can be agreed as acceptable.

NOTE 1 The choice of the single-value reference service life of the component (RSLC) for replaceable, non-structural components, can be the expectation value (i.e. the mean or median) PSLC of the distribution. However, scheduled maintenance plans, when considered alongside other replaceable components or other circumstances, might result in a more conservative choice. This may be covered by local codes, standards or normative requirements applicable for that type of asset.

The communication of the service life prediction and any derived reference service life (RSL) should include the constraints and assumptions in respect of both the asset tested and the operating conditions, in addition to any specific methodology adopted and results of tests undertaken.

NOTE 2 Guidance on service life prediction methods can be found in ISO 15686-3. Service life predictions can be based on evidence from previous use, on comparisons with the known service life of similar components, on tests of degradation in specific conditions or on a combination of these. These predictions form the basis of reference service lives, and therefore of estimates of service life also.

If requiredAn estimated service life (ESL) for an asset shall be undertaken by modifying a RSL applicable to such an asset. This shall include consideration of how conditions assumed in generating the RSL differ from the in-use conditions to which the asset is subjected, i.e. the object-specific in-use conditions

As much information as possible on the conditions under which the RSL is generated should be communicated when RSL data, including the relevant reference in-use conditions.

RSL data are formatted into an RSL data record that shall contain the RSL value and the appurtenant reference in-use conditions as well as additional information on critical properties, performance requirements and data quality.

NOTE RSL data do not include the actual values of the factors A to G but the information needed to estimate these factors.

For the generation of new PSLDC data, the methodology as described in 5.1 shall be used.

NOTE 2 Guidance on service life estimation methods can be found in ISO 15686-3. For the provision of RSL data, the capturing of existing general data of any kind is acceptable.

Providers of RSL data shall consider:

— sources of existing general data;

— assess such data in terms of RSL data

— analysis of data from feedback from practice as described in ISO 15686-7.

NOTE Providers of data can include manufacturers of building and construction products, test laboratories, national assessment bodies and technical approval organizations, database holders or other data providers.

The process of providing RSL data shall follow the process shown in Figure 1.

Formatting general data as RSL data shall be undertaken in accordance with the considerations indicated in Clause 5.1 generally.

Figure 1 — The process of selecting data

Data providers shall consider whether the following types of data can provide or influence the selection of suitable RSLs:

— Manufacturers of building and construction products in-house information concerning the service life and durability of their products. Manufacturers’ data may be made public in documents such as a product’s declarations, , company websites or databases.

— National building codes may list typical service lives of components, and Boards of Agreement and technical approval bodies in local states may provide assessments of service lives in their certificates or reports of national product evaluation services.

— Other sources of information such as databases, published tables based on empirical time-to-failure assessments and judgements of experienced professionals. More scattered empirical knowledge from previous experience and observations of similar constructions or materials in similar in-use conditions should also be used.

NOTE 1 The vast amount of existing data of scattered quality constitutes an important source of information, especially if data generated based on ISO 15686-2 are not available.

The quality and completeness of data should be considered, and data should be utilised which captures the assumed conditions on which the RSL is based in preference to those sources which do not provide this information.

RSL data shall contain at least a general description of the material or component and data on service life, in an indicated outdoor (or indoor) environment, and should encompass all relevant information concerning the generation of the service-life data. The following types of data shall form part of an RSL data record:

— in-use conditions structured according to all corresponding factor categories;

— critical properties;

— performance requirements.

Users of RSL data shall:

a) find service-life data;

b) assess the appropriateness of using these data as RSL data.

The process of selecting RSL data shall follow the process outlined in Figure 1.

As an alternative to selecting RSL data, users of data may select general data, in which case the data are then structured and formatted as RSL data. Selection of general data shall follow the process outlined in Figure 1.

The normal route of selection of data is expected to become selection of RSL data, however, if general data is the only available source of information the process shown in Figure 1 should be used.

In determining whether to use RSL data or general data, service life planners shall consider the following.

Databases providing RSL data records have the advantage that data are given in a format ready for that purpose. However, this does not imply that RSL data records should always be selected even if available. When general data on service life, other than RSL data records, are of higher quality or more appropriate for the object-specific in-use conditions, these shall be used.

If data found are not given as RSL data records, data shall first be assessed taking account of the following considerations:

Ensuring that data are appropriate to use for the object of the service life planning process. Caution should be taken where the critical properties deemed to degrade in the object-specific in-use conditions are not all encompassed by data. This can result in a critical property being excluded, which may then possibly become the terminal critical property. For a building element, data on the weakest part is sufficient when this can be identified, e.g. from experience.

Data shall be rejected when:

— the degradation agents that are deemed to be significant for the expected degradation process(es) are not all encompassed;

— any one of the degradation agents excluded is known or believed to be a part of the object- specific in-use conditions; and

— the performance requirement(s) assumed differs significantly from that specified for the object and the RSL cannot be modified accurately enough in accordance with these difference(s).

Data based on reference in-use conditions similar to the object-specific in-use conditions shall always be sought. Such data:

— keeps the modifying factors as close to unity as possible, thus minimizing the probability of error in the ESL due to uncertainty in the way mechanisms of degradation are taken into account by the modifications; and

— minimizes the probability that a critical property not encompassed by data becomes the terminal critical property.

To judge which reference in-use conditions are most similar to, or deviates the least from, the object- specific in-use conditions, consideration shall only be made to the in-use conditions or degradation agents known to, or believed to, have the greatest impact on the service life.

For the final choice of data, the data quality shall be considered, noting that a higher quality grade of data mayt justify the use of such data, even though it may be generated at more deviating in-use conditions.

NOTE The ISO 8000 series provides guidance on data quality particularly relevant to the exchange of data between organisations. It also provides guidance on data creating, storing, maintaining, restoring, exploiting and presenting. Generally high-quality data are clear, consistent and sustainable. However the terminology used differs from that in this Standard so caution may be required.

If data selected are not given as RSL data records, such formatting shall be carried out in accordance with 5.4. The purpose of this is threefold.

a) Having all RSL data in the same format facilitates the systematic work of the service life planning, particularly when it comes to comparison with alternative data.

b) A common data format facilitates the structuring of the documentation of the service life planning, and assist when possible future revisions occur.

c) By reporting data used in the form of RSL data records, grounds are prepared to create or expand individual and third-party databases of RSL data.

The use of open data formats rather than vendor specific formats should be considered as they provide clear guidance on definitions and formats of data. This may facilitate data exchange between parties.

One specific method used in service life estimation is the factor method, while the application of other possible methods shall also be generally acceptable as long as they provide reliable estimations.

The factor method shall be used to obtain an ESL of a component of a design object by modifying an RSL by considering the differences between the object-specific and the reference in-use conditions under which the RSL is valid. The differences are classified in relation to seven factor categories.

The factor method can be applied at different levels of sophistication, from working as a simple checklist to more complex calculations. When the factor method is being used, the level shall be selected taking into account factors such as the actual purpose of the estimation, type and quality of available data and models, skill level and type of expertise of the user(s) making the estimation, and resources and time available for the calculation.

At checklist level, a step-by-step procedure shall be carried out, in which the difference between the object-specific and the reference in-use condition within each factor category (see Table A.1) is considered and estimated separately in respective steps.

Using experience, in combination with the overall set of differences, an estimation of the ESL shall be made by taking into account the influence on the RSL that these both are likely to cause.

At multiplication level the estimation of the ESL shall be carried out by multiplying the value of RSL by numerical factors A to G. These shall comprise:

— A: component quality;

— B: design;

— C: installation;

— D: external environment;

— E: internal environment;

— F: usage;

— G: maintenance.

NOTE 1 The factor method originates from work carried out in Japan, details are published by the Architectural Institute of Japan in the English Edition of the Principal Guide for Service Life Planning of Buildings.

NOTE 2 The Factor method is a way of bringing together consideration of agents or conditions that are likely to affect service life. The method enables a systematic assessment when reference in-use conditions do not fully match the anticipated in-use conditions, which is normally the case. Its use mayt bring together the experience of designers, observations, intentions of managers, and manufacturers’ assurances, as well as data from test houses.

NOTE 3 This document does not give guidance on how to estimate the modification part or the values of factors A to G, using given reference in-use conditions and the object-specific in-use conditions. The use of the factor method is described in ISO 15686-3. The factors are listed in 6.2.5.

A residual service life estimate maybe prepared during the service life of the building or constructed asset if required by the client. It represents an estimate of the period of remaining service life during which the asset retains acceptable performance. The person generating the estimate shall take account of project or asset-specific anticipated operating conditions and environment.

The residual life estimate shall also take account of any changes in performance requirements since the original design was undertaken. The person responsible shall also take account of the current condition of the asset.

NOTE 1 Guidance on condition surveys is given in ISO 15686-7:2017, Clause 5. This describes provision of a standardised framework for planning, terms and methods of such surveys, together with standardised definitions. These may reflect local codes and standards, or other normative guidance for the specific type of asset or project. It also provides for specific reporting requirements for the condition assessment including how condition is described and measured and how the extent of the survey reflects the level of assessment dependent on the purpose of the survey. The scope of the survey may also include capturing the actual operating conditions, which may be relevant to assessment of residual service life.

NOTE 2 ISO 15686-7:2017, Annex A gives guidance on environmental classification and assessment of microenvironments.

The residual service life shall be predicted from the performance assessment of the asset and the limit state or acceptance level as described in ISO 15686-7:2017, 5.3.5. This covers assessment of failure, consequences of failure, risk of a non-acceptable failure occurring and probability that performance deteriorates further. The relationship between acceptability and performance level is shown in Figure 2.

Figure 2 — Degradation of a component and its relation to service life distributions and physical modelling (Method 2)

6.1.1 The service life performance review process: summary

The service life review shall be undertaken using a systematic process to set out the properties which affect the service life of a constructed asset for a given set of performance requirements to determine that adequate measures are in place to achieve the expected service life. The service life reviewer shall consider the following aspects:

— The service life of a component or building is a response to use conditions to achieve defined performance requirements. The same component may have very different service lives under different use conditions for different functional requirements.

— Use conditions and functional requirements may vary with time, these may predicable or not. There will invariably be a degree of uncertainty about service lives in practice. This means that service life data may be considered in terms of ‘an estimate’ or expressed in terms of probability and conditional on a set of assumptions.

EXAMPLE The functional requirements of a galvanized low carbon steel railing can be to resist a lateral load of 100 N. If located on a beach promenade it might have an estimated service life of 10 to 20 years. Whereas the same railing might have an estimated service life of over 100 years where it is installed inside a dry, heated building. If however, the functional requirement includes a clause along the lines of “maximum extent of surface corrosion 5 % of the surface area”, the railing located next to the coast can have a service life of 5 years. In this example the key intrinsic properties of the constructed asset are: chemical composition of the galvanizing, galvanizing thickness and grade and cross section of steel as well as design and installation practice (for example ensuring that configuration of the railing allows moisture to be shed from its surface.). The key extrinsic agents in this case would relate to atmospheric corrosivity, which at its simplest can be expressed as an average annual corrosion rate for galvanizing. More comprehensive (and complex) approach to agents which affect service life may be taken if warranted.

The service life review process shall include six stages as shown in Figure 3.

Figure 3 — Service life review process

6.1.2 Information framework for service life reviews

When undertaking service life planning of assets, the following options shall be considered in accordance with the categorisation in this clause.

Table 3: Constructed asset hierarchy

Table 4: Types of service life

Table 5: Methods of service life determination

Table 6: Service life metrics

6.1.3 Constructed asset hierarchy

Table 1 shall be used to categorise construction assets by function or unit which can be treated separately for service life review. Communication of the categorisation of the review shall be included with the review.

Table 3 — Hierarchy of constructed assets

NOTE These definitions are not rigid. For example an insulated glass unit c be treated as an assembly, comprising components such as glass, spacer bars, desiccant; sealant. Or the insulated glass unit may be treated as component being a finished product from a manufacturer.

6.1.4 Types of service life

The service life review shall be clear about the type of service life – using the descriptions shown in Table 2.

Where the service life review references other service life data the type of service life shall be make clear.

Table 4 — Types of service life

6.1.5 Determining service life

The reviewer shall include information on sources of service lives and methods of determining service lives in accordance with Table 3.

Table 5 — Sources and methods for service life determination

6.1.6 Service life metrics

The required metrics to express service lives shall be agreed in advance. Table 4 gives examples of the range of service life values which are used in the construction industry.

Table 6 — Service life metrics

6.2 Service life review process in detail

6.2.1 General

The information specified in 6.2.2 to 6.2.7 shall be communicated for each stage in the process.

6.2.2 Stage 1: scope and aims of the service life review

Stage 1 shall include a statement of the significance or the purpose of the service life in the context of the asset and associated requirements (such as business risk, health and safety risks) and where it fits in with the life cycle (Table 1), degree of acceptable risk, type of service life (Table 2).

Detailed questions which shall be considered include:

— Is the purpose or scope of the service life assessment clear?

— Is the temporal context of the service life review clear?

— Is the degree of acceptable risk clearly stated or applicable?

— Is the service life type clear? (Table 1)

6.2.3 Stage 2: the constructed asset(s)

Stage 2 shall include a statement with a definition of the physical boundary of the asset.

Table 1 gives an overview of the hierarchy of constructed assets.

Detailed questions which shall be considered include:

— Does the description and information about the asset provide relevant material, physical or chemical data to inform service life factors? (see also component quality in service life factors)

— Are there dependencies which should be considered?

— Are relevant functional issues taken into account?

— What is the condition of existing assets?

6.2.4 Stage 3: service life information

Stage 3 shall include a statement of the service life to be reviewed, and the condition which determines end of service life.

Detailed questions which shall be considered include:

— What type of service life is being reviewed? (Table 1)

— How was the service life determined? (Table 3)

— Is this method appropriate?

— Does the service life relate to the end of life criteria?

— Have the key failure modes been considered?

— Have other service life criteria been taken into account (e.g. technical, legal, social, economic, functional and aesthetic obsolescence)?

— Is there up to date corroborating service life data which reflects the conditions of the constructed asset under review?

— Are the service life factors reasonable and have they been taken into account in the service life value? (see service life factors)

— Is the service life value reasonable? (Table 4)

6.2.5 Stage 4: service life factors

Stage 4 shall include a statement of the factors which influence service life. These shall comprise:

— Component quality

— Design

— Installation

— External environment

— Internal environment

— Usage

— Maintenance

Detailed questions which shall be considered include:

— Is there adequate data about the constructed asset to determine its capacity to resist the expected agents of deterioration or maintain the required performance levels.

— Have relevant design issues been taken into account?

— Typical points of reference: good practice guidance, standards.

— Typical issues: design of interfaces, junctions and protective features.

— Have relevant installation issues been taken into account?

— Typical points of reference: good practice guidance, standards.

— Typical issues: installation at interfaces, junctions and of protective features.

— Have relevant external environment issues been taken into account?

— Is there relevant and applicable data for the expected external environment for the location of the asset being reviewed?

— Have relevant internal environment issues been taken into account?

— Is there relevant and applicable data for the expected internal environment for the location of the asset being reviewed?

— Have relevant usage issues been taken into account?

— Is there relevant and applicable data for the usage for the location of the asset being reviewed?

— Have relevant maintenance issues been taken into account?

Where these questions are relevant and if appropriate, any risk assessments undertaken in respect of each shall be described.

6.2.6 Stage 5: service life review

Stage 5 shall include a review of the evidence and data for the service life in the context of known or accepted service life information.

NOTE The service life review process can be iterative. The quality of the review is related to expertise of the reviewer, information flows and time allocated to carry out the review.

6.2.7 Stage 6: Service life review report

The report shouldinclude (as applicable) the suggested headings in Annex A.

6.2.8 The principle of proportionality

A reviewer of service life should undertake a proportionate review of the evidence for the level of criticality and sensitivity or risk that failures represent.

NOTE 1 A fully comprehensive review of service life is rarely likely to be justified because of the expense and time required to carry it out. See ISO 15686-1 4.2 NOTE.

Selection of the most critical components shall be based on one or more of the following:

— items that could cause major problems, for example process shutdown, security, health and safety or environmental hazard, or high-cost repair;

— permanent items intended to have a service life in excess of the constructed asset’s design life (or the period to first refurbishment);

— items exposed to specific hazards on a particular site, for example where a standard garage canopy is to be built in an exposed marine environment;

— untried items, for example a new formulation for a protective coating;

— the need to limit maintenance and repair to the resources (finance or manpower) available;

— experience of the deterioration of similar constructed assets in similar circumstances, for example from examination of feedback and in use records.

NOTE 2 ISO 15686-1 sets out a hierarchy of failure consequences (e.g. danger to life, interruption of asset use) that may be useful in selecting components for review.

Whatever the selection approach adopted, the reviewer shall take account of the whole and all relevant site, use conditions and to any unusual or innovative features of the use case.

1. 
   (informative)
   
   Service life review reports
   1. Service life reviews at different stages in the asset life cycle
      1. General

Service life review may be carried out at any stage in the asset life cycle and a broader focus than solely service life metrics may be considered. Service life reviews can be carried out to provide reasonable assurance that measures necessary to achieve satisfactory performance over time have been addressed and implemented.

Table A.1 considers a range of service life reviews.

Table A.1 — Service life review related to asset life cycle

• • 1. Review types

Service life reviews may be carried in numerous ways:

— Internal review is carried out alongside existing internal project and design management procedures.

— A second-party review is carried out by a person from within the same organization or within the project team, but independent of the activity being reviewed.

— A third-party review is carried out by a person or organization wholly independent of the activity being reviewed.

— A third option of internal reviews followed by external reviews may also be adopted, whereby the documented outcomes of the review process form the inputs into the review process.

NOTE ISO 9004 provides detailed guidance on the implementation of structured in-house design reviews at the conclusion of each phase of design development.

• • 1. Pre-requisites for service life reviews

The reviewer should be suitably qualified.

Relevant information should be made available to the reviewer.

• • 1. Parties and roles in the service life review process

Roles and responsibilities of all parties involved in a service life review should be clearly set out.

• • 1. Documentation

Service life reviews are reliant on relevant documentation relating to the scope and evidence in support of service life performance.

Changes to project information should be provided to the reviewer.

Document register. The reviewer should maintain records of all reference documents and other information received which forms the basis of the review.

• 1. Service life review report

The output of the service life review report may include some or all of the following headings:

— the date and circumstances of the review;

— details of the project;

— identification of the reviewer or review team;

— the review criteria, scope and objectives, including relevant client requirements;

— a list (including issue numbers and dates) of the reference documents provided for review, including identification of drawings, surveys, calculations, specifications and other data;

— a summary of the findings of any previous reviews for the project and of any corrective action taken;

— the review findings, including the reasoning and steps taken to reach those findings;

— corrective action recommended as a result of the review;

— the distribution list for the review statement.

The review should contain the findings or a summary thereof, with reference to the supporting evidence.

The review should identify and report as nonconformity information that is:

— incorrect;

— missing or incomplete;

— contradictory;

— impractical or ill defined;

— unsupported by reliable data; or

— still uncorrected, i.e. where a nonconformity identified in a previous review remains uncorrected.

BIBLIOGRAPHY

ISO 15686‑5, Buildings and constructed assets — Service life planning — Part 5: Life-cycle costing

ISO 9004:2018, Quality management — Quality of an organization — Guidance to achieve sustained success

The English Editon of Principal Guide for Service Life Planning of Buildings – Architectural Institution of Japan. 1993.