Environmental management — Life cycle assessment — Examples of application of ISO 14041 to goal and scope definition and inventory analysis

Provides examples about practices in carrying out an Live Cycle Inventory analysis (LCI) as a means of satisfying certain provisions of ISO 14041. These examples are only a sample of the possible cases satisfying the provisions of the standard. They should be read as offering a way of ways rather than the unique way of applying the standard. Also they reflect only certain portions of a LCI study.

Management environnemental — Analyse du cycle de vie — Exemples d'application de l'ISO 14041 traitant de la définition de l'objectif et du champ d'étude et analyse de l'inventaire

L'objet du présent Rapport Technique est de fournir des exemples sur les méthodes de réalisation d'un inventaire du cycle de vie comme moyen de satisfaire certaines dispositions de l'ISO 14041. Ces exemples ne représentent qu'un échantillon des exemples susceptibles de répondre aux dispositions de la norme. Il convient de les considérer comme un "moyen" ou "des moyens" représentatifs plutôt que comme "la seule façon" de mettre en pratique ladite norme. A ce titre, ils ne correspondent également qu'à certaines parties d'une étude de l'inventaire du cycle de vie. Il convient de noter que les exemples présentés dans le présent Rapport Technique ne sont pas exclusifs et qu'il existe de nombreux autres exemples permettant d'illustrer les études méthodologiques décrites. Ils ne constituent que des parties d'une étude complète d'inventaire du cycle de vie.

Ravnanje z okoljem - Ocenjevanje življenjskega cikla - Primeri uporabe ISO 14041 za opredelitev cilja in namena ter inventarizacijo

General Information

Status
Withdrawn
Publication Date
29-Mar-2000
Withdrawal Date
29-Mar-2000
Current Stage
9599 - Withdrawal of International Standard
Start Date
23-May-2012
Completion Date
23-May-2012

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TECHNICAL ISO/TR
REPORT 14049
First edition
2000-03-15
Environmental management— Life cycle
assessment — Examples of application of
ISO 14041 to goal and scope definition and
inventoryanalysis
Management environnemental — Analyse du cycle de vie — Exemples
d'application de l'ISO 14041 traitant de la définition de l'objectif
et du champ d'étude et analyse de l'inventaire
Reference number
ISO/TR 14049:2000(E)
ISO 2000
---------------------- Page: 1 ----------------------
ISO/TR 14049:2000(E)
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ii © ISO 2000 – All rights reserved
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ISO/TR 14049:2000(E)
Page
Contents

1 Scope....................................................................................................................................................... 1

2 Technical Introduction ............................................................................................................................ 1

3 Examples of developing functions, functional units and reference flows............................................ 3

4 Examples of distinguishing functions of comparative systems ........................................................... 6

5 Examples of establishing inputs and outputs of unit processes and system boundaries ................ 10

6 Examples of avoiding allocation........................................................................................................... 17

7 Examples of allocation.......................................................................................................................... 21

8 Example of applying allocation procedures for recycling................................................................... 24

9 Examples of conducting data quality assessment .............................................................................. 34

10 Examples of performing sensitivity analysis ....................................................................................... 39

© ISO 2000 – All rights reserved iii
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ISO/TR 14049:2000(E)
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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted

by the technical committees are circulated to the member bodies for voting. Publication as an International

Standard requires approval by at least 75 % of the member bodies casting a vote.

In exceptional circumstances, when a technical committee has collected data of a different kind from that which is

normally published as an International Standard ("state of the art", for example), it may decide by a simple majority

vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature

and does not have to be reviewed until the data it provides are considered to be no longer valid or useful.

ISO/TR 14049 was prepared by Technical Committee ISO/TC 207, Environmental management, Subcommittee

SC 5, Life cycle assessment..
iv © ISO 2000 – All rights reserved
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ISO/TR 14049:2000(E)
Introduction

The heightened awareness of the importance of environmental protection, and the possible impacts associated

with products manufactured and consumed, has increased the interest in the development of methods to better

comprehend and reduce these impacts. One of the techniques being developed for this purpose is Life Cycle

Assessment (LCA). To facilitate a harmonized approach, a family of standards on life cycle assessment (LCA),

including ISO 14040, ISO 14041, ISO 14042 and ISO 14043 and this document are being developed by ISO.

These International Standards describe principles of conducting and reporting LCA studies with certain minimal

requirements.

This Technical Report provides supplemental information to the International Standard, ISO 14041, Environmental

management - Life cycle assessment - Goal and scope definition and life cycle inventory analysis, based on

several examples on key areas of the Standard in order to enhance the understanding of the requirements of the

standard.

Methodological requirements for conducting LCA studies are provided in the following International Standards

concerning the various phases of LCA:

⎯ ISO 14040: Environmental management - Life cycle assessment - Principles and framework.

⎯ ISO 14041: Environmental management - Life cycle assessment - Goal and scope definition and

inventory analysis.

⎯ ISO 14042: Environmental management - Life cycle assessment - Life cycle impact assessment.

⎯ ISO 14043: Environmental management - Life cycle assessment - Life cycle interpretation.

© ISO 2000– All rights reserved v
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TECHNICAL REPORT ISO/TR 14049:2000(E)
Environmental management — Life cycle assessment —
Examples of application of ISO 14041 to goal and scope
definition and inventory analysis
1 Scope

This Technical Report provides examples about practices in carrying out an Life Cycle Inventory analysis (LCI) as

a means of satisfying certain provisions of ISO 14041. These examples are only a sample of the possible cases

satisfying the provisions of the standard. They should be read as offering “a way” or “ways” rather than the “unique

way” of applying the standard. Also they reflect only certain portions of an LCI study.

It should be noted that the examples presented in this Technical Report are not exclusive and that many other

examples exist to illustrate the methodological issues described. The examples are only portions of a complete LCI

study.
2 Technical Introduction
The examples focus on six key areas of ISO 14041 as indicated in Table 1.

In some key areas there is more than one example. The reason is that in many cases more than one practice

exists. The decision about the application of one or the other practices is goal dependent and can vary e.g. from the

product system under investigation or in the stages over the life cycle. The examples are described in the context

of the corresponding provisions of the standard and with the specific use.

In the description of the different cases, whenever possible, the following structure has been adopted :

– Context of the standard
– Overview
– Description of the examples
© ISO 2000 – All rights reserved 1
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ISO/TR 14049:2000(E)
Table 1 – Cross references between ISO 14041 and examples in this document
ISO 14041 Examples in ISO/TR 14049
0 Introduction
1 Scope
2 Normative reference
3 Terms and definitions
4 LCI components
4.1 General
4.2 Product system
4.3 Unit process
4.4 Data categories
4.5 Modelling product systems
5 Definition of goal and scope
5.1 General
5.2 Goal of the study
5.3 Scope of the study
5.3.1 General

5.3.2 Function, functional unit and 3 Examples of developing functions, functional units

reference flow and reference flows
4 Examples of distinguishing functions of
comparative systems
5.3.3 Initial system boundaries
5.3.4 description of data categories

5.3.5 Criteria for initial inclusion of 5 Examples of establishing the inputs, outputs and

inputs and outputs boundary of unit process
10 Examples of performing sensitivity analysis
5.3.6 Data quality requirements 9 Examples of conducting data quality assessment
5.3.7 Critical review
6 Inventory analysis
6.1 General
6.2 Preparing for data collection
6.3 Data collection 9 Examples of conducting data quality assessment
6.4 Calculation procedures
6.4.1 General
6.4.2 Validation of data 9 Examples of conducting data quality assessment
6.4.3 Relating data to the unit
process

6.4.4 Relating data to functional unit 3 Examples of developing functions, functional

and data aggregation units and reference flows

6.4.5 Refining the system boundaries 10 Examples of performing sensitivity analysis

6.5 Allocation of flows and releases
6.5.1 General
6.5.2 Allocation principles 6 Examples of avoiding allocation
6.5.3 Allocation procedure 6 Examples of avoiding allocation
7 Examples of applying allocation

6.5.4 Allocation procedures for reuse 8 Examples of applying allocation procedures for

and recycling recycling

7 Limitation of LCI (interpreting LCI results) 9 Examples of conducting data quality assessment

10 Examples of performing sensitivity analysis
8 Study report
ANNEX
A Example of a data collection sheet
B Examples of different allocation
procedures
2 © ISO 2000 – All rights reserved
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ISO/TR 14049:2000(E)
3 Examples of developing functions, functional units and reference flows
3.1 Context of the standard
ISO 14041 states in 5.3.2 that:

⎯ In defining the scope of an LCA study, a clear statement on the specification of the functions (performance

characteristics) of the product shall be made.

⎯ The functional unit defines the quantification of these identified functions. The functional unit shall be

consistent with the goal and scope of the study.

⎯ One of the primary purposes of a functional unit is to provide a reference to which the input and output

data are normalized (in a mathematical sense). Therefore the functional unit shall be clearly defined and

measurable.

⎯ Having defined the functional unit, the amount of product which is necessary to fulfil the function shall be

quantified. The result of this quantification is the reference flow.
and in 6.4.4 that:

⎯ Based on the flow chart and systems boundaries, unit processes are interconnected to allow calculations

on the complete system. This is accomplished by normalizing the flows of all unit processes in the system

to the functional unit. The calculation should result in all system input and output data being referenced to

the functional unit.
3.2 Overview

In defining a functional unit and determining the reference flows, the following steps can be distinguished:

⎯ identification of functions;
⎯ selection of functions and definition of functional unit;

⎯ identification of performance of the product and determination of the reference flow.

The sequence of these steps is depicted in Figure 1 using the example of paint. This example is also used in the

following text (3.3 to 3.5). Further examples are given in 3.6.
© ISO 2000 – All rights reserved 3
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ISO/TR 14049:2000E)
3.3
Product Functions
Identification of functions
-Surface protection
Wall paint
- Colouring
- etc.
3.4
Relevant function (s) for the particular LCA
Selection of functions and
definition of functional unit
Colouring wall of type A with paint
Functional unit
Colouring 20 m of wall type A with opacity
98% and durability of 5 years
3.5
Identification of performance of
Performance of the product
the product and determination
of the reference flow
Paint A covers 8,7 m per litre
Reference flow
2,3 l of paint A

Note: It is possible to start with either the product or with the function itself.

Figure 1 – Overview of the example
3.3 Identification of functions

The purpose of the functional unit is to quantify the service delivered by the product system. The first step is thus to

identify the purpose served by the product system, i.e. its function or functions.

The starting point for this procedure may be a specific product to be studied (e.g. wall paint) or it may be the final

need or goal, which in some cases may be fulfilled by several distinct products (e.g. wall decoration, which may be

fulfilled by both paint and wallpaper or a combination of these).

The functions are typically related to specific product or process properties, each of which may:

⎯ fulfil specific needs and thereby have a use value, which typically creates economic value to the supplier

of the product,

⎯ affect the functioning of other economic systems (e.g. wallpaper may have a - small - insulation effect,

thus affecting the heat requirement of the building).
4 © ISO 2000 – All rights reserved
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ISO/TR 14049:2000(E)
3.4 Selection of functions and definition of functional unit

Not all functions may be relevant for a particular LCA. Thus, out of all the possible functions, the relevant ones

must be identified.

For a solid interior wall, for example, surface protection may be unnecessary, while colouring is a relevant function

of paint.

Subsequently, the relevant functions are quantified in the functional unit, which may be expressed as a

combination of different parameters.

For wall colouring, the functional unit will typically have to specify the area to be covered (e.g. 20 m ), the type of

wall (especially regarding its absorption and binding properties), the ability of the paint to hide the underlying

surface (e.g. 98 % opacity), and its useful life (e.g. 5 years).

In the case of multifunctional units, the different quantities are sometimes linked, e.g. a wall covering insulation

material may be available with a pre-coloured surface, which makes colouring unnecessary, thus delivering both

insulation and colouring. The functional unit could then be:

"20 m wall covering with a heat resistance of 2 m·K/W, with a coloured surface of 98 % opacity, not requiring any

other colouring for 5 years".
Other examples of multifunctional units are given in Table 2.
Table 2 – Examples of functional units for systems with multiple functions.
Example No. (1) (2)
System Paper recycling Cogeneration
Functions - Recovery of waste paper, and - Generation of electric power, and
- Production of de-inked pulp - Production of steam
- etc. - etc.

Selected function - Recovery of waste paper, or - Generation of electric power, or

for a particular LCA
- Production of de-inked pulp - Production of steam

Functional unit - Recovery of 1 000 kg waste paper, - Generation of 100 MW electricity, or

- Production of 300 000 kg steam per
- Production of 1 000 kg pulp for hour at 125 °C and 0,3 MPa (3 bar)
newsprint

3.5 Identification of performance of the product and determination of the reference flow

Having defined a certain functional unit, the next task is to determine the quantity of product which is necessary to

fulfil the function quantified by the functional unit. This reference flow is related to the product's performance, and is

typically determined as the result of a standardized measurement method. Of course, the nature of this

measurement and calculation depends on the studied product.

For paint, the reference flow is typically expressed as the amount of litres necessary for covering the surface area

as defined by the functional unit. For example, in a standardized test, paint A may be determined to cover 8,7 m

per litre (i.e. the performance of the product). Using the example illustrated in Figure 1, this requires 2,3 l to cover

the 20 m of the functional unit, provided that the conditions in the standardized test are similar to those required by

the functional unit (with regard to surface type and opacity).
© ISO 2000 – All rights reserved 5
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ISO/TR 14049:2000(E)

The functional unit may already be expressed in terms of quantities of products, so that the functional unit and the

reference flow are identical. Table 2 gives examples of such functional units, which are already expressed in terms

of quantities of products.
3.6 Additional examples

The following three examples further illustrate the procedure in developing functions, functional units, and

reference flows.

Table 3 – Further examples of developing functions, functional units, and reference flows

Example No. (1) (2) (3)
Product Light bulb Bottle Hand drying
Functions - Providing illumination - Protection of beverage - Drying hands
- Generating heat - Facilitating handling - Removing bacteria
-etc. - Part of product image -etc.
-etc.

Selected function Providing illumination Protection of beverage Drying hands (hygienic

for a particular (outdoor lamp only) function judged
LCA irrelevant)
Functional unit 300 lx in 50 000 h 50 000 l of beverage 1 000 pairs of hands
matching the daylight protected between dried
spectrum at 5 600 K. tapping and consumption

Performance of 100 lx with a lifetime of 0,5 l one-way bottle One paper towel for

the product 10 000 h drying one hand
Reference flow 15 daylight bulbs of 100 000 one-way bottles 2 000 paper towels
100 lx with a lifetime of of volume 0,5 l
10 000 hours
4 Examples of distinguishing functions of comparative systems
4.1 Context of the standard
ISO 14041 states in 5.3.2 that:

⎯ Comparisons between systems shall be made on the basis of the same function, quantified by the same

functional unit in the form of their reference flows.

⎯ If additional functions of any of the systems are not taken into account in the comparison of functional

units, then these omissions shall be documented. For example, systems A and B perform functions x and

y which are represented by the selected functional unit, but system A also performs function z, which is

not represented in the functional unit. It shall then be documented that function z is excluded from its

functional unit. As an alternative, systems associated with the delivery of function z may be added to the

boundary of system B to make the systems more comparable. In these cases, the processes selected

shall be documented and justified.
4.2 Overview

When comparing product systems, special attention has to be made to confirm that the comparison is based on the

same functional unit and equivalent methodological considerations, such as performance, system boundaries, data

quality, allocation procedures, decision rules on evaluating inputs and outputs. In this chapter, some possible

approaches will be described and illustrated by examples.

The general steps to be taken in comparative studies are illustrated in Figure 2.

6 © ISO 2000 – All rights reserved
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ISO/TR 14049:2000(E)
4.3
Identification of functions (as in 3.3.)
Identification and
Selection of functions
Selection of functions and definition of functional
unit (as in 3.4)
Identification of performance of the product and
4.4
determination of the reference flows
Equivalence of reference flows
Yes
Are the reference
Can be compared
Flows equivalent?
Can the reference flows
Cannot be compared
be made equivalent?
Yes
Adjusting performance differences
4.5
Adjusting for performance differences
Figure 2 – Overview of the steps in comparative studies
4.3 Identification and selection of functions

The definition of the functional unit is closely bound to the goal of the study. If the goal is to compare product

systems, special care will have to be paid in order to ensure that the comparison is valid, that any additional

functions are identified and described, and that all relevant functions are taken into account.

Example 1: A study on waste management should include other functions than simply disposing of waste (i.e. the functions

performed by the recycling systems in providing recycled material or energy).

Example 2: A study on electric household equipment should include the waste heat delivered to the building in which the

equipment operates, as this influence the amount of heating and/or cooling required.

For comparative studies, the selection of functions becomes much more important than in non-comparative studies.

Referring to the functions in Table 3:

⎯ For bottles (example 2), leaving out of the image function of the packaging may lead to comparison of

packagings that are technically similar (i.e. containing the same volume of beverage), but which the

producer or customer will not accept as comparable.

⎯ For hand-drying systems (example 3), leaving out the hygienic function may be regarded as

unacceptable, e.g. in the food industry, where the bacteria-removing ability of paper towels may be

regarded as such an advantage that a comparison to electrical hand-drying systems may not even be

considered.
4.4 Equivalence of reference flows

The functional unit of the paint example from Clause 3 was "colouring 20 m of wall type A with opacity 98 % and

durability of 5 years". This functional unit can be supplied by several different reference functions:

© ISO 2000 – All rights reserved 7
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ISO/TR 14049:2000(E)
2,3 l of paint A,
1,9 l of paint B,
1,7 l of paint C, etc.

These reference flows will have been calculated based on a test using standard conditions, concerning e.g. surface

type and opacity.

The standardised test conditions and measurement methods must be appropriate to the intended comparison: In

the hand drying example (example 3 in Table 3), it may be irrelevant to use a standardized test based on the

technical properties of the paper such as mass, absorption-power and tensile strength, if the actual weight of paper

used depends on the dispenser design. A more appropriate measure would then be data collected by weighing the

paper stock at the start and the end of an adequate period in which the number of hands dried are determined by

electronic surveillance of actual wash basins located in relevant institutions. Similarly, technical specifications of an

electrical hand drier, such as the volume of air and its temperature, may be irrelevant as a basis for calculating the

reference function, if the actual running time of the device is fixed by other factors, e.g. a built-in timer. Then, all

that is needed is the running time and the electrical capacity of the equipment.

In the case of the light bulb (example 1 in Table 3), the functional unit of "300 lx in 50 000 h" may be provided by:

⎯ 5 times 3 bulbs of 100 lx with a lifetime of 10 000 h each, or
⎯ 10 times 2 bulbs of 150 lx with a lifetime of 5 000 h each.

The underlying premises of comparing 3 bulbs of 100 lx with 2 bulbs of 150 lx are:

⎯ that the light spectrum of the two bulb types are comparable (or that the difference is acceptable to the

user),

⎯ that the 3 and 2 bulbs, respectively, can be placed so that the distribution of light is equal (or that the

difference is acceptable to the user),

⎯ that the sockets and other fixtures are not affected by the choice (in which case they would have to be

included in the comparison).

Also, the two light bulbs were regarded as comparable in spite of their difference in lifetime. This difference is

simply taken into account in the calculation of the reference flow. However, for long-lived products, such as

refrigerators with lifetimes of 10 or 20 years, technology development may be a factor that cannot be disregarded.

One refrigerator with a lifetime of 20 years cannot simply be compared to two successive, present-day refrigerators

with a lifetime of 10 years. The refrigerators available 10 years from now are certain to be more energy efficient (i.e.

lower energy input per functional unit) than the present, the energy efficiency of the second refrigerator of the 10 +

10 option must be determined by a trend projection, while the energy efficiency of the 20 years option is fixed.

The 100 000 one-way bottles of volume 0,5 l (example 2 in Table 3) may technically fulfil the same function of

protecting 50 000 l of beverage, as would 12 500 returnable bottles of volume 0,4 l with a reuse rate of 90 %.

However, in some situations the consumer may not always be able to distinguish between bottles of different

volumes or masses. If the consumer regards 1 bottle equal to 1 bottle, the total consumption of beverage will

decrease when the returnable bottles are introduced. In this case, the packaging cannot be studied independent of

its contents. This is an example of the "No"-arrow leaving to the right in Figure 2. Of course, the goal of the study

may then be redefined allowing for a comparison of beverage plus packaging taking into account the changes in

consumption.

Another example of non-comparable functions (the "No"-arrow to the right in Figure 2), is that of two freezers, one

with and one without quick-freeze option. If the quick-freeze option is regarded as an essential function by the

consumer, the two freezers are simply not comparable and they cannot be made comparable by any calculation or

system expansion. The same is true for the examples given at the end of 4.3.
8 © ISO 2000 – All rights reserved
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ISO/TR 14049:2000(E)

In some systems with multiple functions, such as those in Table 2, the functions may be separated and delivered

by several systems:

⎯ Disposing the waste paper in an incineration plant and producing the pulp from virgin fibres may provide

the same functional unit as the paper recycling system.

⎯ Separate power and district heating units, respectively producing only electric power and only heat, may

deliver the same functional unit as the co-generation plant.

However, some functions may be so intimately linked that separation is not possible. For example, the heat

generation of a light bulb cannot be detached from its primary function.

In other situations, separations of two linked functions may be technically possible, but due to other aspects, the

two separate functions may still not be regarded as comparable to the joint functions. An example of this is the

combined freezer-refrigerator, which may or may not be compared to a freezer and separate refrigerator,

depending on the acceptability of this choice to the consumer (the latter option will typically take up more space

than a combined option with the same internal volumes).

Note that in most of the examples above, the equivalence of two products is determined by user acceptance. This

acceptance, and thus whether two products are regarded as comparable or not, may be influenced by the price of

the alternatives and by the additional information given along with the products, e.g. information on their

environmental performance. Thus, for the purposes of product development or strategic management, it may be

reasonable to compare two products which are not immediately regarded as equivalent, but where it is assumed

that they will be regarded as equivalent under specific conditions of price and information.

4.5 Adjusting for performance differences

In those cases where the reference flows are immediately equivalent (as in the paint example at the top of 4.4) no

adjustment is necessary.

In other cases, adjustment is necessary. The adjustment procedure follows the same principles as for co-product

allocation, i.e. the preferred option is modification of the system boundaries to avoid the performance difference. In

some cases, when this modification is not possible or feasible, allocation may be applied. In this section, examples

are given of both options.

In the case of the light bulb in 4.4, it may be necessary to adjust the one of the systems to be compared (expanding

it with an extra bulb socket). Another, more radical, example of such a system expansion or reconsideration of the

studied functions, is that mentioned under the bottle example in 4.4, where the inclusion of the beverage was

necessary.

A comparison of refrigerators may be based on their internal and/or external volume. The primary function is

obviously related to their internal volume, but the external volume may a determining function, if the refrigerator is

to be fitted into an existing kitchen. If the external volume is required to be equal, the internal volume may differ

because of differences in insulation thickness. This can only be adjusted for by assuming differences in behaviour

of the user (e.g. shopping more often, storing certain items outside the refrigerator, adding another secondary

refrigerator elsewhere in the house). Each of these changes in behaviour will involve changes in different

processes, which then have to be included in the study. If, on the other hand, the internal volume is required to be

equal, a change in insula
...

SLOVENSKI STANDARD
SIST-TP ISO/TR 14049:2008
01-november-2008
Ravnanje z okoljem - Ocenjevanje življenjskega cikla - Primeri uporabe ISO 14041
za opredelitev cilja in namena ter inventarizacijo

Environmental management - Life cycle assessment - Examples of application of ISO

14041 to goal and scope definition and inventory analysis
Management environnemental - Analyse du cycle de vie - Exemples d'application de

l'ISO 14041 traitant de la définition de l'objectif et du champ d'étude et analyse de

l'inventaire
Ta slovenski standard je istoveten z: ISO/TR 14049:2000
ICS:
13.020.10 Ravnanje z okoljem Environmental management
13.020.60 Življenjski ciklusi izdelkov Product life-cycles
SIST-TP ISO/TR 14049:2008 en,fr

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP ISO/TR 14049:2008
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SIST-TP ISO/TR 14049:2008
TECHNICAL ISO/TR
REPORT 14049
First edition
2000-03-15
Environmental management— Life cycle
assessment — Examples of application of
ISO 14041 to goal and scope definition and
inventoryanalysis
Management environnemental — Analyse du cycle de vie — Exemples
d'application de l'ISO 14041 traitant de la définition de l'objectif
et du champ d'étude et analyse de l'inventaire
Reference number
ISO/TR 14049:2000(E)
ISO 2000
---------------------- Page: 3 ----------------------
SIST-TP ISO/TR 14049:2008
ISO/TR 14049:2000(E)
PDF disclaimer

This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not

be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this

file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this

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ii © ISO 2000 – All rights reserved
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SIST-TP ISO/TR 14049:2008
ISO/TR 14049:2000(E)
Page
Contents

1 Scope....................................................................................................................................................... 1

2 Technical Introduction ............................................................................................................................ 1

3 Examples of developing functions, functional units and reference flows............................................ 3

4 Examples of distinguishing functions of comparative systems ........................................................... 6

5 Examples of establishing inputs and outputs of unit processes and system boundaries ................ 10

6 Examples of avoiding allocation........................................................................................................... 17

7 Examples of allocation.......................................................................................................................... 21

8 Example of applying allocation procedures for recycling................................................................... 24

9 Examples of conducting data quality assessment .............................................................................. 34

10 Examples of performing sensitivity analysis ....................................................................................... 39

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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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted

by the technical committees are circulated to the member bodies for voting. Publication as an International

Standard requires approval by at least 75 % of the member bodies casting a vote.

In exceptional circumstances, when a technical committee has collected data of a different kind from that which is

normally published as an International Standard ("state of the art", for example), it may decide by a simple majority

vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature

and does not have to be reviewed until the data it provides are considered to be no longer valid or useful.

ISO/TR 14049 was prepared by Technical Committee ISO/TC 207, Environmental management, Subcommittee

SC 5, Life cycle assessment..
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Introduction

The heightened awareness of the importance of environmental protection, and the possible impacts associated

with products manufactured and consumed, has increased the interest in the development of methods to better

comprehend and reduce these impacts. One of the techniques being developed for this purpose is Life Cycle

Assessment (LCA). To facilitate a harmonized approach, a family of standards on life cycle assessment (LCA),

including ISO 14040, ISO 14041, ISO 14042 and ISO 14043 and this document are being developed by ISO.

These International Standards describe principles of conducting and reporting LCA studies with certain minimal

requirements.

This Technical Report provides supplemental information to the International Standard, ISO 14041, Environmental

management - Life cycle assessment - Goal and scope definition and life cycle inventory analysis, based on

several examples on key areas of the Standard in order to enhance the understanding of the requirements of the

standard.

Methodological requirements for conducting LCA studies are provided in the following International Standards

concerning the various phases of LCA:

⎯ ISO 14040: Environmental management - Life cycle assessment - Principles and framework.

⎯ ISO 14041: Environmental management - Life cycle assessment - Goal and scope definition and

inventory analysis.

⎯ ISO 14042: Environmental management - Life cycle assessment - Life cycle impact assessment.

⎯ ISO 14043: Environmental management - Life cycle assessment - Life cycle interpretation.

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SIST-TP ISO/TR 14049:2008
TECHNICAL REPORT ISO/TR 14049:2000(E)
Environmental management — Life cycle assessment —
Examples of application of ISO 14041 to goal and scope
definition and inventory analysis
1 Scope

This Technical Report provides examples about practices in carrying out an Life Cycle Inventory analysis (LCI) as

a means of satisfying certain provisions of ISO 14041. These examples are only a sample of the possible cases

satisfying the provisions of the standard. They should be read as offering “a way” or “ways” rather than the “unique

way” of applying the standard. Also they reflect only certain portions of an LCI study.

It should be noted that the examples presented in this Technical Report are not exclusive and that many other

examples exist to illustrate the methodological issues described. The examples are only portions of a complete LCI

study.
2 Technical Introduction
The examples focus on six key areas of ISO 14041 as indicated in Table 1.

In some key areas there is more than one example. The reason is that in many cases more than one practice

exists. The decision about the application of one or the other practices is goal dependent and can vary e.g. from the

product system under investigation or in the stages over the life cycle. The examples are described in the context

of the corresponding provisions of the standard and with the specific use.

In the description of the different cases, whenever possible, the following structure has been adopted :

– Context of the standard
– Overview
– Description of the examples
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Table 1 – Cross references between ISO 14041 and examples in this document
ISO 14041 Examples in ISO/TR 14049
0 Introduction
1 Scope
2 Normative reference
3 Terms and definitions
4 LCI components
4.1 General
4.2 Product system
4.3 Unit process
4.4 Data categories
4.5 Modelling product systems
5 Definition of goal and scope
5.1 General
5.2 Goal of the study
5.3 Scope of the study
5.3.1 General

5.3.2 Function, functional unit and 3 Examples of developing functions, functional units

reference flow and reference flows
4 Examples of distinguishing functions of
comparative systems
5.3.3 Initial system boundaries
5.3.4 description of data categories

5.3.5 Criteria for initial inclusion of 5 Examples of establishing the inputs, outputs and

inputs and outputs boundary of unit process
10 Examples of performing sensitivity analysis
5.3.6 Data quality requirements 9 Examples of conducting data quality assessment
5.3.7 Critical review
6 Inventory analysis
6.1 General
6.2 Preparing for data collection
6.3 Data collection 9 Examples of conducting data quality assessment
6.4 Calculation procedures
6.4.1 General
6.4.2 Validation of data 9 Examples of conducting data quality assessment
6.4.3 Relating data to the unit
process

6.4.4 Relating data to functional unit 3 Examples of developing functions, functional

and data aggregation units and reference flows

6.4.5 Refining the system boundaries 10 Examples of performing sensitivity analysis

6.5 Allocation of flows and releases
6.5.1 General
6.5.2 Allocation principles 6 Examples of avoiding allocation
6.5.3 Allocation procedure 6 Examples of avoiding allocation
7 Examples of applying allocation

6.5.4 Allocation procedures for reuse 8 Examples of applying allocation procedures for

and recycling recycling

7 Limitation of LCI (interpreting LCI results) 9 Examples of conducting data quality assessment

10 Examples of performing sensitivity analysis
8 Study report
ANNEX
A Example of a data collection sheet
B Examples of different allocation
procedures
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3 Examples of developing functions, functional units and reference flows
3.1 Context of the standard
ISO 14041 states in 5.3.2 that:

⎯ In defining the scope of an LCA study, a clear statement on the specification of the functions (performance

characteristics) of the product shall be made.

⎯ The functional unit defines the quantification of these identified functions. The functional unit shall be

consistent with the goal and scope of the study.

⎯ One of the primary purposes of a functional unit is to provide a reference to which the input and output

data are normalized (in a mathematical sense). Therefore the functional unit shall be clearly defined and

measurable.

⎯ Having defined the functional unit, the amount of product which is necessary to fulfil the function shall be

quantified. The result of this quantification is the reference flow.
and in 6.4.4 that:

⎯ Based on the flow chart and systems boundaries, unit processes are interconnected to allow calculations

on the complete system. This is accomplished by normalizing the flows of all unit processes in the system

to the functional unit. The calculation should result in all system input and output data being referenced to

the functional unit.
3.2 Overview

In defining a functional unit and determining the reference flows, the following steps can be distinguished:

⎯ identification of functions;
⎯ selection of functions and definition of functional unit;

⎯ identification of performance of the product and determination of the reference flow.

The sequence of these steps is depicted in Figure 1 using the example of paint. This example is also used in the

following text (3.3 to 3.5). Further examples are given in 3.6.
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3.3
Product Functions
Identification of functions
-Surface protection
Wall paint
- Colouring
- etc.
3.4
Relevant function (s) for the particular LCA
Selection of functions and
definition of functional unit
Colouring wall of type A with paint
Functional unit
Colouring 20 m of wall type A with opacity
98% and durability of 5 years
3.5
Identification of performance of
Performance of the product
the product and determination
of the reference flow
Paint A covers 8,7 m per litre
Reference flow
2,3 l of paint A

Note: It is possible to start with either the product or with the function itself.

Figure 1 – Overview of the example
3.3 Identification of functions

The purpose of the functional unit is to quantify the service delivered by the product system. The first step is thus to

identify the purpose served by the product system, i.e. its function or functions.

The starting point for this procedure may be a specific product to be studied (e.g. wall paint) or it may be the final

need or goal, which in some cases may be fulfilled by several distinct products (e.g. wall decoration, which may be

fulfilled by both paint and wallpaper or a combination of these).

The functions are typically related to specific product or process properties, each of which may:

⎯ fulfil specific needs and thereby have a use value, which typically creates economic value to the supplier

of the product,

⎯ affect the functioning of other economic systems (e.g. wallpaper may have a - small - insulation effect,

thus affecting the heat requirement of the building).
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3.4 Selection of functions and definition of functional unit

Not all functions may be relevant for a particular LCA. Thus, out of all the possible functions, the relevant ones

must be identified.

For a solid interior wall, for example, surface protection may be unnecessary, while colouring is a relevant function

of paint.

Subsequently, the relevant functions are quantified in the functional unit, which may be expressed as a

combination of different parameters.

For wall colouring, the functional unit will typically have to specify the area to be covered (e.g. 20 m ), the type of

wall (especially regarding its absorption and binding properties), the ability of the paint to hide the underlying

surface (e.g. 98 % opacity), and its useful life (e.g. 5 years).

In the case of multifunctional units, the different quantities are sometimes linked, e.g. a wall covering insulation

material may be available with a pre-coloured surface, which makes colouring unnecessary, thus delivering both

insulation and colouring. The functional unit could then be:

"20 m wall covering with a heat resistance of 2 m·K/W, with a coloured surface of 98 % opacity, not requiring any

other colouring for 5 years".
Other examples of multifunctional units are given in Table 2.
Table 2 – Examples of functional units for systems with multiple functions.
Example No. (1) (2)
System Paper recycling Cogeneration
Functions - Recovery of waste paper, and - Generation of electric power, and
- Production of de-inked pulp - Production of steam
- etc. - etc.

Selected function - Recovery of waste paper, or - Generation of electric power, or

for a particular LCA
- Production of de-inked pulp - Production of steam

Functional unit - Recovery of 1 000 kg waste paper, - Generation of 100 MW electricity, or

- Production of 300 000 kg steam per
- Production of 1 000 kg pulp for hour at 125 °C and 0,3 MPa (3 bar)
newsprint

3.5 Identification of performance of the product and determination of the reference flow

Having defined a certain functional unit, the next task is to determine the quantity of product which is necessary to

fulfil the function quantified by the functional unit. This reference flow is related to the product's performance, and is

typically determined as the result of a standardized measurement method. Of course, the nature of this

measurement and calculation depends on the studied product.

For paint, the reference flow is typically expressed as the amount of litres necessary for covering the surface area

as defined by the functional unit. For example, in a standardized test, paint A may be determined to cover 8,7 m

per litre (i.e. the performance of the product). Using the example illustrated in Figure 1, this requires 2,3 l to cover

the 20 m of the functional unit, provided that the conditions in the standardized test are similar to those required by

the functional unit (with regard to surface type and opacity).
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The functional unit may already be expressed in terms of quantities of products, so that the functional unit and the

reference flow are identical. Table 2 gives examples of such functional units, which are already expressed in terms

of quantities of products.
3.6 Additional examples

The following three examples further illustrate the procedure in developing functions, functional units, and

reference flows.

Table 3 – Further examples of developing functions, functional units, and reference flows

Example No. (1) (2) (3)
Product Light bulb Bottle Hand drying
Functions - Providing illumination - Protection of beverage - Drying hands
- Generating heat - Facilitating handling - Removing bacteria
-etc. - Part of product image -etc.
-etc.

Selected function Providing illumination Protection of beverage Drying hands (hygienic

for a particular (outdoor lamp only) function judged
LCA irrelevant)
Functional unit 300 lx in 50 000 h 50 000 l of beverage 1 000 pairs of hands
matching the daylight protected between dried
spectrum at 5 600 K. tapping and consumption

Performance of 100 lx with a lifetime of 0,5 l one-way bottle One paper towel for

the product 10 000 h drying one hand
Reference flow 15 daylight bulbs of 100 000 one-way bottles 2 000 paper towels
100 lx with a lifetime of of volume 0,5 l
10 000 hours
4 Examples of distinguishing functions of comparative systems
4.1 Context of the standard
ISO 14041 states in 5.3.2 that:

⎯ Comparisons between systems shall be made on the basis of the same function, quantified by the same

functional unit in the form of their reference flows.

⎯ If additional functions of any of the systems are not taken into account in the comparison of functional

units, then these omissions shall be documented. For example, systems A and B perform functions x and

y which are represented by the selected functional unit, but system A also performs function z, which is

not represented in the functional unit. It shall then be documented that function z is excluded from its

functional unit. As an alternative, systems associated with the delivery of function z may be added to the

boundary of system B to make the systems more comparable. In these cases, the processes selected

shall be documented and justified.
4.2 Overview

When comparing product systems, special attention has to be made to confirm that the comparison is based on the

same functional unit and equivalent methodological considerations, such as performance, system boundaries, data

quality, allocation procedures, decision rules on evaluating inputs and outputs. In this chapter, some possible

approaches will be described and illustrated by examples.

The general steps to be taken in comparative studies are illustrated in Figure 2.

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4.3
Identification of functions (as in 3.3.)
Identification and
Selection of functions
Selection of functions and definition of functional
unit (as in 3.4)
Identification of performance of the product and
4.4
determination of the reference flows
Equivalence of reference flows
Yes
Are the reference
Can be compared
Flows equivalent?
Can the reference flows
Cannot be compared
be made equivalent?
Yes
Adjusting performance differences
4.5
Adjusting for performance differences
Figure 2 – Overview of the steps in comparative studies
4.3 Identification and selection of functions

The definition of the functional unit is closely bound to the goal of the study. If the goal is to compare product

systems, special care will have to be paid in order to ensure that the comparison is valid, that any additional

functions are identified and described, and that all relevant functions are taken into account.

Example 1: A study on waste management should include other functions than simply disposing of waste (i.e. the functions

performed by the recycling systems in providing recycled material or energy).

Example 2: A study on electric household equipment should include the waste heat delivered to the building in which the

equipment operates, as this influence the amount of heating and/or cooling required.

For comparative studies, the selection of functions becomes much more important than in non-comparative studies.

Referring to the functions in Table 3:

⎯ For bottles (example 2), leaving out of the image function of the packaging may lead to comparison of

packagings that are technically similar (i.e. containing the same volume of beverage), but which the

producer or customer will not accept as comparable.

⎯ For hand-drying systems (example 3), leaving out the hygienic function may be regarded as

unacceptable, e.g. in the food industry, where the bacteria-removing ability of paper towels may be

regarded as such an advantage that a comparison to electrical hand-drying systems may not even be

considered.
4.4 Equivalence of reference flows

The functional unit of the paint example from Clause 3 was "colouring 20 m of wall type A with opacity 98 % and

durability of 5 years". This functional unit can be supplied by several different reference functions:

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2,3 l of paint A,
1,9 l of paint B,
1,7 l of paint C, etc.

These reference flows will have been calculated based on a test using standard conditions, concerning e.g. surface

type and opacity.

The standardised test conditions and measurement methods must be appropriate to the intended comparison: In

the hand drying example (example 3 in Table 3), it may be irrelevant to use a standardized test based on the

technical properties of the paper such as mass, absorption-power and tensile strength, if the actual weight of paper

used depends on the dispenser design. A more appropriate measure would then be data collected by weighing the

paper stock at the start and the end of an adequate period in which the number of hands dried are determined by

electronic surveillance of actual wash basins located in relevant institutions. Similarly, technical specifications of an

electrical hand drier, such as the volume of air and its temperature, may be irrelevant as a basis for calculating the

reference function, if the actual running time of the device is fixed by other factors, e.g. a built-in timer. Then, all

that is needed is the running time and the electrical capacity of the equipment.

In the case of the light bulb (example 1 in Table 3), the functional unit of "300 lx in 50 000 h" may be provided by:

⎯ 5 times 3 bulbs of 100 lx with a lifetime of 10 000 h each, or
⎯ 10 times 2 bulbs of 150 lx with a lifetime of 5 000 h each.

The underlying premises of comparing 3 bulbs of 100 lx with 2 bulbs of 150 lx are:

⎯ that the light spectrum of the two bulb types are comparable (or that the difference is acceptable to the

user),

⎯ that the 3 and 2 bulbs, respectively, can be placed so that the distribution of light is equal (or that the

difference is acceptable to the user),

⎯ that the sockets and other fixtures are not affected by the choice (in which case they would have to be

included in the comparison).

Also, the two light bulbs were regarded as comparable in spite of their difference in lifetime. This difference is

simply taken into account in the calculation of the reference flow. However, for long-lived products, such as

refrigerators with lifetimes of 10 or 20 years, technology development may be a factor that cannot be disregarded.

One refrigerator with a lifetime of 20 years cannot simply be compared to two successive, present-day refrigerators

with a lifetime of 10 years. The refrigerators available 10 years from now are certain to be more energy efficient (i.e.

lower energy input per functional unit) than the present, the energy efficiency of the second refrigerator of the 10 +

10 option must be determined by a trend projection, while the energy efficiency of the 20 years option is fixed.

The 100 000 one-way bottles of volume 0,5 l (example 2 in Table 3) may technically fulfil the same function of

protecting 50 000 l of beverage, as would 12 500 returnable bottles of volume 0,4 l with a reuse rate of 90 %.

However, in some situations the consumer may not always be able to distinguish between bottles of different

volumes or masses. If the consumer regards 1 bottle equal to 1 bottle, the total consumption of beverage will

decrease when the returnable bottles are introduced. In this case, the packaging cannot be studied independent of

its contents. This is an example of the "No"-arrow leaving to the right in Figure 2. Of course, the goal of the study

may then be redefined allowing for a comparison of beverage plus packaging taking into account the changes in

consumption.

Another example of non-comparable functions (the "No"-arrow to the right in Figure 2), is that of two freezers, one

with and one without quick-freeze option. If the quick-freeze option is regarded as an essential function by the

consumer, the two freezers are simply not comparable and they cannot be made comparable by any calculation or

system expansion. The same is true for the examples given at the end of 4.3.
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In some systems with multiple functions, such as those in Table 2, the functions may be separated and delivered

by several systems:

⎯ Disposing the waste paper in an incineration plant and producing the pulp from virgin fibres may provide

the same functional unit as the paper recycling system.

⎯ Separate power and district heating units, respectively producing only electric power and only heat, may

deliver the same functional unit as the co-generation plant.

However, some functions may be so intimately linked that separation is not possible. For example, the heat

generation of a light bulb cannot be detached from its primary function.

In other situations, separations of two linked functions may be technically possible, but due to other aspects, the

two separate functions may still not be regarded as comparable to the joint functions. An example of this is the

combined freezer-refrigerator, which may or may not be compared to a freezer and separate refrigerator,

depending on the acceptability of this choice to the consumer (the latter option will typically take up more space

than a combined option with the same internal volumes).

Note that in most of the examples above, the equivalence of two products is determined by user acceptance. This

acceptance, and thus whether two products are regarded as comparable or not, may be influenced by the price of

the alternatives and by the additional information given along with the products, e.g. information on their

environmental performance. Thus, for the purposes of product development or strategic management, it may be

reasonable to compare two products which are not immediately regarded as equivalent, but where it is assumed

that they will be regarded as equivalent under specific conditions of price and information.

4.5 Adjusting for performance differences

In those cases where the reference flows are immediately equivalent (as in the paint example at the top of 4.4) no

adjustment is necessary.

In other cases, adjustment is necessary. The adjustment procedure follows the same principle

...

RAPPORT ISO/TR
TECHNIQUE 14049
Première édition
2000-03-15
Management environnemental — Analyse
du cycle de vie — Exemples d'application
de l'ISO 14041 traitant de la définition de
l'objectif et du champ d'étude et analyse de
l'inventaire
Environmental management — Life cycle assessment — Examples of
application of ISO 14041 to goal and scope definition and inventory
analysis
Numéro de référence
ISO/TR 14049:2000(F)
ISO 2000
---------------------- Page: 1 ----------------------
ISO/TR 14049:2000(F)
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ISO/TR 14049:2000(F)
Sommaire

Introduction.................................................................................................................................................................v

1 Domaine d'application...................................................................................................................................1

2 Introduction technique..................................................................................................................................1

3 Exemples de développement de fonctions, d'unités fonctionnelles et de flux de référence ................3

4 Exemples de différenciation des fonctions des systèmes comparatifs ..................................................6

5 Exemples de détermination d'entrants et de sortants de processus élémentaires et frontières

du système ...................................................................................................................................................10

6 Exemples pour éviter une imputation .......................................................................................................17

7 Exemples d'imputation................................................................................................................................22

8 Exemple d'application des règles d'imputation pour le recyclage.........................................................25

9 Exemples de réalisation d'évaluation de la qualité des données...........................................................36

10 Exemples de réalisation d'analyse de sensibilité.....................................................................................40

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ISO/TR 14049:2000(F)
Avant propos

L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de

normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée aux

comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du comité

technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales, en

liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec la Commission

électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.

Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI, Partie 3.

La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes

internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur publication

comme Normes internationales requiert l'approbation de 75 % au moins des comités membres votants.

Exceptionnellement, lorsqu'un comité technique a réuni des données de nature différente de celles qui sont

normalement publiées comme Normes internationales (ceci pouvant comprendre des informations sur l'état de la

technique par exemple), il peut décider, à la majorité simple de ses membres, de publier un Rapport technique. Les

Rapports techniques sont de nature purement informative et ne doivent pas nécessairement être révisés avant que

les données fournies ne soient plus jugées valables ou utiles.

L'ISO/TR 14049 a étéélaboré par le comité technique ISO/TC 207, Management environnemental, sous-comité

SC 5, Analyse du cycle de vie.
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ISO/TR 14049:2000(F)
Introduction

La sensibilisation accrue de l'importance de la protection de l'environnement, et les éventuels impacts associés à la

fabrication et à la consommation de produits, a augmenté l'intérêt porté au développement de méthodes

permettant de mieux comprendre et donc de réduire ces impacts. Une des techniques développées à cet effet est

l'Analyse du Cycle de Vie. Pour permettre une approche harmonisée, l'ISO développe toute une série de normes

sur l'analyse du cycle de vie, comprenant l'ISO 14040, l'ISO 14041, l'ISO 14042 et l'ISO 14043 ainsi que le présent

document. Ces Normes internationales décrivent les principes concernant la réalisation et la communication des

études d'analyse du cycle de vie, selon certaines exigences minimales.

Le présent rapport technique fournit des informations complémentaires concernant la norme internationale

ISO 14041, Management environnemental – Analyse du cycle de vie – Définition de l’objectif et du champ d’étude

et analyse de l’inventaire, à partir de plusieurs exemples portant sur des points clé de la norme afin de mieux

comprendre ses exigences.

Des exigences méthodologiques permettant de mener des études d'analyse du cycle de vie sont données dans les

Normes internationales suivantes qui traitent des différentes phases de l'analyse du cycle de vie :

� ISO 14040 : Management environnemental – Analyse du cycle de vie – Principes et cadre.

� ISO 14041 : Management environnemental – Analyse du cycle de vie – Définition de l’objectif et du

champ d’étude et analyse de l’inventaire.

� ISO 14042 : Management environnemental – Analyse du cycle de vie –Évaluation de l’impact du cycle de

vie.

� ISO 14043 : Management environnemental – Analyse du cycle de vie – Interprétation du cycle de vie.

© ISO 2000 – Tous droits réservés v
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RAPPORT TECHNIQUE ISO/TR 14049:2000(F)
Management environnemental — Analyse du cycle de vie —
Exemples d'application de l'ISO 14041 traitant de la définition de
l'objectif et du champ d'étude et analyse de l'inventaire
1 Domaine d'application

L'objet du présent Rapport Technique est de fournir des exemples sur les méthodes de réalisation d'un inventaire

du cycle de vie comme moyen de satisfaire certaines dispositions de l'ISO 14041. Ces exemples ne représentent

qu'un échantillon des exemples susceptibles de répondre aux dispositions de la norme. Il convient de les

considérer comme un "moyen" ou "des moyens" représentatifs plutôt que comme "la seule façon" de mettre en

pratique ladite norme. A ce titre, ils ne correspondent également qu'à certaines parties d'une étude de l'inventaire

ducycledevie.

Il convient de noter que les exemples présentés dans le présent Rapport Technique ne sont pas exclusifs et qu'il

existe de nombreux autres exemples permettant d'illustrer les études méthodologiques décrites. Ils ne constituent

que des parties d'une étude complète d’inventaire du cycle de vie.
2 Introduction technique

Les exemples mettent l'accent sur six points clé de la norme ISO 14041 comme indiqué dans le Tableau 1.

Certains points clé sont illustrés par plusieurs exemples. Cela est dû au fait que dans de nombreux cas, il existe

plusieurs méthodes. La décision d'appliquer telle ou telle méthode dépend de l'objectif et peut varier par exemple

en fonction du système de produits en cours d'étude ou des étapes du cycle de vie. Les exemples sont décrits

dans le contexte des dispositions correspondantes de la norme et de l'usage spécifique.

Dans la mesure du possible, les différents exemples sont décrits selon la structure suivante :

Contexte de la norme
Aperçu
Description des exemples
© ISO 2000 – Tous droits réservés 1
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ISO/TR 14049:2000(F)

Tableau 1 — Correspondances entre l'ISO 14041 et les exemples du présent document

ISO 14041 Exemples dans l’ISO/TR 14049
0 Introduction
1 Domaine d'application
2Référence normative
3Termesetdéfinitions
4 Composantes d'une analyse de l'inventaire du cycle de vie
4.1 Généralités
4.2 Système de produits
4.3 Processus élémentaire
4.4 Catégories de données
4.5 Modélisation des systèmes de produits
5Définition de l'objectif et du champ de l'étude
5.1 Généralités
5.2 Objectif de l'étude
5.3 Champ de l'étude
5.3.1 Généralités
3Exemplesdedéveloppement de fonctions,
5.3.2 Fonction, unité fonctionnelle et flux de référence
d'unités fonctionnelles et de flux de référence.
4 Exemples de différenciation des fonctions des
systèmes comparatifs
5.3.3 Frontières initiales du système
5.3.4 Description des catégories de données
5Exemplesdedétermination d’entrants et de
5.3.5 Critères pour l'inclusion initiale des entrants et des
sortants de processus élémentaire et frontières du
sortants
système
10 Exemples de réalisation d'analyse de sensibilité
9Exemplesderéalisation d'évaluation de la qualité
5.3.6 Exigences relatives à la qualité des données
des données
5.3.7 Revue critique
6 Analyse de l'inventaire
6.1 Généralités
6.2 Préparation pour le recueil des données
9Exemplesderéalisation d'évaluation de la qualité
6.3 Recueil des données
des données
6.4 Procédures de calcul
6.4.1 Généralités
9Exemplesderéalisation d'évaluation de la qualité
6.4.2 Validation des données
des données
6.4.3 Mise en rapport des données avec le processus
élémentaire
3Exemplesdedéveloppement de fonctions,
6.4.4 Mise en rapport des données avec l'unité fonctionnelle
d'unités fonctionnelles et de flux de référence
et agrégation des données
10 Exemples de réalisation d'analyse de sensibilité
6.4.5 Affinement des frontières du système
6.5 Imputation des flux et dégagements
6.5.1 Généralités
6Exemplespour éviter une imputation
6.5.2 Principes d'imputation
6Exemplespour éviter une imputation
6.5.3 Règles d'imputation
7 Exemples d'imputation
8 Exemple d'application des règles d'imputation pour
6.5.4 Règles d'imputation pour la réutilisation et le recyclage
le recyclage

7 Limitation de l'inventaire du cycle de vie (interprétation des 9Exemplesderéalisation d'évaluation de la qualité

résultats) des données
10 Exemples de réalisation d'analyse de sensibilité
8 Rapport d'étude
ANNEXES
A Exemples d'une fiche de recueil des données
B Exemples de différentes règles d'imputation
2 © ISO 2000 – Tous droits réservés
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ISO/TR 14049:2000(F)
3 Exemples de développement de fonctions, d'unités fonctionnelles et de flux de
référence
3.1 Contexte de la norme
L'ISO 14041 stipule en 5.3.2 que :

� Lorsqu'on définit le champ d'une étude d'analyse du cycle de vie, il faut spécifier de manière claire les

fonctions (caractéristiques de performance) du produit.

� C'est l'unité fonctionnelle qui permet de quantifier les fonctions ainsi identifiées. Elle doit donc être

cohérente avec l'objectif et le champ de l'étude.

� Une unité fonctionnelle sert principalement de référence à partir de laquelle sont (mathématiquement)

normalisées les données d'entrée et de sortie. Il faut donc que l'unité fonctionnelle doit être clairement

définie et mesurable.

� S'agissant d'unité fonctionnelle donnée, il faut mesurer la quantité de produit nécessaire pour remplir la

fonction. Le résultat de la mesure est le flux de référence.
ainsi qu'en 6.4.4 que :

� sur la base du diagramme des flux et des frontières du système, des processus élémentaires sont

interconnectés pour permettre d'effectuer les calculs du système complet. Ceci est réalisé en normalisant

les flux de tous les processus élémentaires dans le système par rapport à l'unité fonctionnelle. Le calcul

conduit, en règle générale, au référencement de toutes les données d'entréeet desortie du système par

rapport à l'unité fonctionnelle.
3.2 Aperçu

Lors de la définition d'une unité fonctionnelle et de la détermination des flux de référence, on peut distinguer les

étapes suivantes :
� identification des fonctions ;
� sélection des fonctions et définition d'une unité fonctionnelle ;

� identification de la performance du produit et déterminationduflux deréférence.

L'exemple de la peinture dans la Figure 1 illustre la séquence de ces étapes. Cet exemple est également repris

dans le texte qui suit (3.3 à 3.5). D'autres exemples sont donnésen3.6.
© ISO 2000 – Tous droits réservés 3
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ISO/TR 14049:2000(F)
3.3
Produit Fonctions
Identification des fonctions
-Protection de la surface
Peinture murale
- Coloration
-etc.
Fonction(s) pertinentes pour l'analyse du cycle de vie
3.4
particulier
Sélection des fonctions et
définition d'une unité fonctionnelle
Coloration d'un mur de type A à l'aide de peinture
Unité fonctionnelle
Coloration de 20 m d'un mur de type A avec une opacité
de 98% et une durabilité de5ans
3.5
Identification de la performance
du produit et détermination du Performance du produit
flux de référence
La peinture A couvre 8,7 m par litre
Flux de référence
2,3 l de peinture A

NOTE Il est possible de commencer soit par le produit soit par l'unité fonctionnelle elle-même.

Figure 1 — Aperçu de l'exemple
3.3 Identification des fonctions

L'objet de l'unité fonctionnelle est de quantifier le service fourni par le système de produits. La première étape

consiste donc à identifier l'objet du système de produits, c'est-à-dire sa fonction ou ses fonctions.

Le point de départ de cette procédure peut être un produit particulier àétudier (par exemple de la peinture murale)

ou bien il peut s'agir du besoin ou de l'objectif final, qui dans certains cas peut être satisfait par plusieurs produits

distincts (par exemple la décoration murale, que l'on peut réaliser avec de la peinture murale ou du papier peint, ou

une combinaison des deux).

Les fonctions sont généralement associées à desproduitsspécifiques ou à des propriétés du processus, chacune

d'entre elles pouvant :

� répondre à des besoins spécifiques et de ce fait avoir une valeur d'usage, ce qui crée d'ordinaire une

valeur économique pour le fournisseur du produit,
4 © ISO 2000 – Tous droits réservés
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ISO/TR 14049:2000(F)

� affecter le fonctionnement d'autres systèmes économiques (le papier peint peut, par exemple, avoir un

petit effet isolant, affectant ainsi l'exigence de chaleur du bâtiment).
3.4 Sélection des fonctions et définition de l'unité fonctionnelle

Toutes les fonctions peuvent ne pas correspondre à une analyse du cycle de vie particulière. Ainsi, parmi toutes

les fonctions possibles, seules les plus pertinentes doivent être identifiées.

S'agissant d'un mur intérieur plein, par exemple, la protection de la surface peut s'avérer inutile, alors que la

couleur est une fonction pertinente de la peinture.

Les fonctions pertinentes sont par conséquent quantifiées dans l'unité fonctionnelle, qui peut être exprimée comme

une combinaison de différents paramètres.

Pour la coloration du mur, l'unité fonctionnelle, typiquement, doit spécifier la zone à couvrir (par exemple 20 m²), le

type de mur (notamment ses propriétés d'absorption et de liaison), l'aptitude de la peinture à cacher la surface

sous-jacente (par exemple 98 % d'opacité), et sa durée de vieutile(par exemple5ans).

Dans le cas des unités multifonctionnelles, les différentes quantités sont parfois liées : par exemple, un matériau

d'isolation des murs peut être disponible en couleur prédéfinie, ce qui rend la coloration inutile, puisque l'isolation et

la peinture sont fournies en même temps. L'unité fonctionnelle pourrait alors être :

"Un mur couvert sur 20 m²,d'une résistance thermique de 2 m K/W avec une surface peinte sur 98 % ne

nécessitant pas d'autre coloration pendant 5 ans."
Le Tableau 2 donne d'autres exemples d'unités multifonctionnelles.
Tableau 2 – Exemples d'unités fonctionnelles pour systèmes à fonctions multiples
Exemple n° (1) (2)
Système Recyclage de papier Cogénération

Fonctions - Valorisation de vieux papiers et -Génération d'énergie électrique, et

- Production de pâte désencrée - Production de vapeur
-etc. -etc.

Fonction choisie pour une - Valorisation de vieux papiers, ou -Génération d'énergie électrique, ou

analyse du cycle de vie
particulière - Production de pâte désencrée - Production de vapeur

Unité fonctionnelle - Récupération de 1 000 kg de -Génération de 100 MW d'électricité,

vieux papiers, ou ou
- Production de 1 000 kg de pâte - Production de 300 000 kg de
pour papier journal vapeur par heure à 125°Cet
0,3 MPA (3 bar)

3.5 Identification de la performance du produit et détermination du flux de référence

Aprèsavoir défini une certaine unité fonctionnelle, l'étape suivante consiste à déterminer la quantité de produit

nécessaire pour remplir la fonction mesurée par l'unité fonctionnelle. Ce flux de référence est liéà la performance

du produit, et est généralement déterminé commelerésultat d'une méthode de mesure normalisée. Il va de soi

que la nature de cette mesure et de ce calcul dépend du produit étudié.
© ISO 2000 – Tous droits réservés 5
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ISO/TR 14049:2000(F)

En ce qui concerne la peinture, le flux de référence est généralement exprimé comme la quantité de litres

nécessaire pour couvrir la superficie définie par l'unité fonctionnelle. Dans un essai normalisé, par exemple, la

peinture A peut être déterminée pour couvrir 8,7 m² par litre (c'est-à-dire la performance du produit). A la lumière

de l'exemple illustré en Figure 1, il faut 2,3 l pour couvrir les 20 m² de l'unité fonctionnelle, sous réserve que les

conditions de l'essai normalisé soient similaires à celles exigées par l'unité fonctionnelle (en termes de type de

surface et d'opacité).

On peut déjà exprimer l'unité fonctionnelle en terme de quantités de produits, de sorte que l'unité fonctionnelle et le

flux de référence soient identiques. Le Tableau 2 donne des exemples de telles unités fonctionnelles déjà

exprimées en termes de quantitésdeproduits.
3.6 Exemples supplémentaires

Les trois exemples suivants illustrent davantage la procédurededéveloppement de fonctions, d'unités

fonctionnelles et de flux de référence.

Tableau 3 — Autres exemples de développement de fonctions, d'unités fonctionnelles et de flux de

référence
Exemple n° (1) (2) (3)
Produit Ampoule électrique Bouteille Séchage des mains
Fonctions - Eclairage -Protectiondelaboisson -Séchage des mains
-Génération de chaleur - Manipulation facilitée - Elimination des
-etc. - Partie de l'image du bactéries
produit -etc.
-etc.
Fonction choisie pour une Eclairage Protection de la boisson Séchage des mains
analyse du cycle de vie (uniquement lampe (fonction hygiénique
particulière extérieure) jugée non pertinente)
Unité fonctionnelle 300 lx en 50 000 h 50 000 l de boisson 1 000 paires de mains
correspondant au spectre protégés entre le séchées
de la lumière à 5 600 K. soutirage et la
consommation

Performance du produit 100 lx d'une duréedevie Bouteille non consignée Une serviette en papier

de 10 000 h de 0,5 l pour sécher une main

Flux de référence 15 ampoules de 100 lx 100 000 bouteilles non 2 000 serviettes en papier

d'une duréede vie de consignées de 0,5 l
10 000 heures
4 Exemples de différenciation des fonctions des systèmes comparatifs
4.1 Contexte de la norme
L'ISO 14041 stipule en 5.3.2 que :

� C'est sur la base des flux de référence que s'effectuent les comparaisons entre systèmes pour une même

fonction quantifiée par la même unité fonctionnelle.

� Si la comparaison des unités fonctionnelles ignore des fonctions supplémentaires de l'un ou l'autre des

systèmes, ces omissions doivent être consignées par écrit. Par exemple, les systèmes A et B exécutent

des fonctions x et y qui sont représentées par l'unité fonctionnelle choisie, mais le système A effectue

aussi la fonction z qui n'est pas représentée dans l'unité fonctionnelle. Il doit être clairement indiqué que la

fonction z est exclue de cette unité fonctionnelle. Autre possibilité, des systèmes associés à l'exécution de

la fonction z peuvent être ajoutés à la frontière du système B pour rendre les systèmes plus comparables.

Dans ce cas, les processus choisis doivent être documentésetjustifiés.
6 © ISO 2000 – Tous droits réservés
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ISO/TR 14049:2000(F)
4.2 Aperçu

Lorsque l'on compare des systèmes de produits, il faut s'assurer que la comparaison est fondéesur la même unité

fonctionnelle et des considérations méthodologiques équivalentes, telles que la performance, les frontières du

système, la qualité des données, les règles d'imputation, les règles de décision sur l'évaluation des entrants et

sortants. Dans cet article, des approches possibles sont décrites et illustrées par des exemples.

La Figure 2 représente les principales étapes à suivre lors d'études comparatives.

4.3
Identification des fonctions (comme en 3.3.)
Identification et
sélection des fonctions
Sélection des fonctions et détermination de l'unité
fonctionnelle (comme en 3.4)
Identification de la performance du produit et
4.4
détermination des flux de référence
Equivalence des flux de référence
Oui
Les flux de référence
Peuvent être comparés
sont-ils équivalents ?
Non
Non
Peux-t-on rendre les flux de
Ne peuvent pas être
référence équivalents ?
comparés
Oui
Ajustement des différences de
4.5
Ajustement des différences de
performances
performances
Figure 2 — Aperçudes étapes lors d'études comparatives
4.3 Identification et sélection des fonctions

La définition de l'unité fonctionnelle est étroitement liée à l'objectif de l'étude. Si le but est de comparer des

systèmes de produits, il faudra tout particulièrement s'assurer que la comparaison est valide, que toutes fonctions

supplémentaires sont identifiées et décrites et que toutes les fonctions pertinentes sont prises en compte.

EXEMPLE 1 : Il convient d'inclure dans une étude de gestion des déchets, d'autres fonctions que la simple élimination des

déchets (c'est-à-dire les fonctions exécutées par les systèmes de recyclage qui fournissent un matériau ou une énergie

recyclé).

EXEMPLE 2 : Il convient d'inclure dans une étude d'appareils électriques ménagers la chaleur perdue fournie au bâtiment dans

lequel l'équipement fonctionne, dans la mesure où cela a une incidence sur la quantité de chaleur et/ou de refroidissement

exigé.
© ISO 2000 – Tous droits réservés 7
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ISO/TR 14049:2000(F)

Contrairement aux études non comparatives, la sélection des fonctions s'avère beaucoup plus importante dans les

études comparatives. Sur la base des fonctions données dans le Tableau 3 :

� En ce qui concerne les bouteilles (exemple 2), l'omission de la fonction image de l'emballage peut

entraîner une comparaison des emballages qui sont techniquement similaires (c'est-à-dire qui contiennent

le même volume de boisson), mais que le producteur ou le consommateur refusera de comparer.

� S'agissant des systèmes de séchage de mains (exemple 3), on peut considérer l'omission de la fonction

hygiénique comme inacceptable, par exemple dans l'industrie alimentaire, où la capacité de désinfection

des serviettes en papier peut être considérée comme un avantage tel que la comparaison avec les

systèmes de séchage électrique n'a même pas lieu d'être.
4.4 Equivalence des flux de référence

L'unité fonctionnelle de l'exemple de la peinture de l'article 3 était "coloration de 20 m² d'un mur de type A avec une

opacité de 98 % et une durée de vie de 5 ans." Cette unité fonctionnelle peut être fournie par plusieurs fonctions de

référence différentes :
2,3 l de peinture A,
1,9 l de peinture B,
1,7 l de peinture C, etc.

Cesfluxde référence auront été calculés à partir d'un essai utilisant des conditions normalisées concernant par

exemple le type de surface et l'opacité.

Les conditions de l'essai normalisé et les méthodes de mesure doivent être appropriées à la comparaison prévue :

dans l'exemple du séchage de mains (exemple 3 du Tableau 3), le recours à l'essai normalisé fondé sur les

propriétés techniques du papier telles que la masse, la capacité d'absorption et la résistance à la traction peut être

non pertinent, si le poids réel du papier utilisé dépend de la conception du distributeur automatique. Une mesure

plus appropriée consisterait alors à recueillir des données en pesant le stock de papier au début et à la fin d'une

période donnée durant laquelle le nombre de mains séchées est déterminé au moyen d'une surveillance

électronique des lavabos réels situésdansles établissements concernés. De même, les caractéristiques

techniques d'un séchoir électrique, telles que le volume d'air et sa température, peuvent ne pas s'appliquer au

calcul de la fonction de référence, si le temps d'utilisation réel de l'appareil est déterminé par d'autres facteurs

comme par exemple une minuterie incorporée. Tout ce qui est alors nécessaire est le temps d'utilisation et la

capacitéélectriquedel'équipement.

Dans le cas de l'ampoule électrique (exemple 1 du Tableau 3), l'unité fonctionnelle de "300 lx en 50 000 h" peut

être fournie par :
� 5 fois 3 ampoules de 100 lx d'une durée de vie de 10 000 h chacune, ou
� 10 fois 2 ampoules de 150 lx d'une duréedevie de 5000hchacune.

Les principes sous-jacents à la comparaison des 3 ampoules de 100 lx aux 2 ampoules de 150 lx sont:

� que le spectre de lumière des deux types d'ampoule est comparable (ou la différence est acceptable aux

yeux de l'utilisateur),

� que les 3 ampoules et les 2 ampoules peuvent être disposées de tellesorte queladistributiondelumière

est égale (ou la différence est acceptable aux yeux de l'utilisateur),

� que le choix n'affecte pas les douilles et autres dispositifs (auquel cas, il faudrait les inclure dans la

comparaison).

En outre, malgré leur différence en terme de durée de vie, les deux ampoules électriques étaient considérées

comme comparables. Cette différence est simplement prise en compte dans le calcul du flux de référence.

Cependant, en ce qui concerne les produits à longue durée de vie, tels que les réfrigérateurs dont les durées de

8 © ISO 2000 – Tous droits réservés
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ISO/TR 14049:2000(F)

vie vont de 10 à 20 ans, les progrès technologiques peuvent constituer un facteur non négligeable. Un réfrigérateur

d'une durée de vie de 20 ans ne peut être simplement comparéà deux réfrigérateurs courants successifs d'une

durée de vie de 10 ans. Il est certain que les réfrigérateurs disponibles dans 10 ans vont consommer moins

d'énergie (c'est-à-dire un intrant énergétique plus faible par unité fonctionnelle) que ceux d'aujourd'hui, le

rendement énergétique du second réfrigérateur à option 10 + 10 doit être déterminé par extrapolation alors que le

rendement énergétique de l'option sur 20 ans est fixé.

Les 100 000 bouteilles non consignées de 0,5 l (exemple 2 du Tableau 3) peuvent techniquement remplir la même

fonction relative à la protection des 50 000 l de boisson, tout comme les 12 500 bouteilles consignées de 0,4 l dont

le taux de réutilisation est de 90 %. Cependant, dans certaines situations, le consommateur peut ne pas toujours

être capable de distinguer des bouteilles de volumes ou de masses différents. Si le consommateur considère

qu'une bouteille est égale à une bouteille, l'introduction de bouteilles consignées diminuera la consommation totale

de boisson. Dans ce cas, on ne peut étudier l'emballage sans son contenu. C'est un exemple de la flèche "non"

figurant à droite de la Figure 2. Il va de soi qu'on peut alors redéfinir l'objectif de l'étude, ce qui permet une

comparaison de la boisson plus l'emballage en tenant compte des changements vis à vis de la consommation.

Les deux congélateurs, l'un avec et l'autre sans l'option congélation rapide, sont un autre exemple de fonctions non

comparables (la flèche "non" à droite de la Figure 2). Si le consommateur considère l'option de congélation rapide

comme une fonction essentielle, les deux congélateurs sont tout simplement incomparables et ne peuvent être

rendus comparables sur la base d'aucun calcul ni aucune extension du système. Cela vaut pour les exemples qui

figurent à la finde4.3.
Dans certains systèmes à fo
...

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