EPS as a Life Cycle oriented System Assessment Tool to Facilitate
Industrial Learning about Relations to the Environment
Reine Karlsson, Systems Management and Bengt Steen, Technical Environmental Planning,
Chalmers University of Technology, Géteborg, Sweden
Agneta Wendel, AB Volvo, Goteborg, Sweden
Abstract
Many Swedish companies are interested in readily understandable guidance on environmental
aspects. The computerised assessment tool EPS is designed to meet such information needs in
product design and business decision making. The EPS index methodology enables more explicit
specification of environmental relations, values and trends for evaluated systems. This paper
illustrates how EPS has been used to clarify a life cycle perspective and its validity in a
comparison of a Volvo Environmental Concept Truck and a conventional truck. The explicit
visualization of environmental characteristics has served as a common focus in interdisciplinary
communication and thereby as a foundation in continuous learning.
Introduction
Environmental protection is becoming an increasingly important issue for world industry. In order
to enable sustainable product development and to guide industry to adopt eco-efficiency and a
life-cycle thinking into commerce, there is a need for readily understandable system assessment
tools. One method that has been specially designed to meet the needs by product developers is the
EPS-system (Environmental Priority Strategies in product design). In its first version the EPS
system was developed during 1990 and it has then been further improved in the Product Ecology
Project, a joint three year activity by the Swedish Federation of Industries, 15 major companies,
the Chalmers University of Technology and the Swedish Environmental Research Institute. EPS
is based on the Life Cycle Assessment methodology. The product environmental LCA has been
subject for an intensive development and debate during the last five years. ISO has recently
forwarded an international standard on the LCA procedure (ISO). The EPS systems perspective
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follows this standard. The EPS system has been used in a number of industrial evaluations of, for
example cables, refrigerators, printed electric circuits, gasoline, packaging materials and car parts.
EPS system design
A company is dependent on customer preferences for its products and services. This means that,
a company has to consider its customer societies general environmental view. In the same way as
with other marketing aspects, a company can influence societal preferences in environmental
matters, but it can not go against what its customer wants or invest to much ahead of the market
development. Consequently, this version of EPS environmental load unit, ELU, is designed as a
measure for societal environmental priorities, by means of willingness to pay (WTP) assess-
ments. The basic method evaluates emissions by means of WTP for changes caused by the
emissions on the environment. Raw material resources are evaluated by WTP for alternative
renewable methods to produce comparable utility. For further details see (Steen).
LGA steps according to ISO | EPS characteristics:
[= Goal and scope definition ] [Designers compass]
[Materials & processes]
[Eaventory. mand resource flows |
ty.
is | [Average risk, WIP.
of environmental impacts |]
Figure 1 Some principles of EPS in relation to ISO 14040 standard.
The EPS system has been developed in a top-down approach. The early specifications was based
on what the designers would like to know in order to be able to decide which environmental
concerns to follow in a choice between two concepts. From this basis the methodology,
computer programs and databases was gradually developed to use as much as possible of
existing knowledge from environmental sciences. The input to the models was data on use of
resources and emissions from processes involved in the life cycle of a product, as well as risk
assessment and valuation models for resulting environmental effects. The output of the model is
a measure corresponding to what a fictive global society consisting of ORCD-economies would
|
|
be willing to pay today to avoid the changes in the environment caused by the product life cycle
if it had to suffer from it itself. The measure is expressed in ELU (Corresponding to one ECU).
Below an example will be given of how the EPS system has been used as an environmental
management tool at the Volvo Truck Corporation.
Comparison of an environmental concept truck and a traditional truck
Environmental LCAs always deal with environmental impact in relation to service value. The
main concern in the design of the ECT was to obtain a high service capability, e.g. by a qualified
Driver Control & Information System and by enabling a turning circle as low as 17 m. Volvo has
a long tradition in safety, not only for the driver. In this ECT project it has also been noted that
there are other risks for surrounding systems and humans than the conventionally noted environ-
mental impacts. The ECT is designed as a city vehicle and for example the cab design takes a
strong interest in the eye contact between the driver and other city space users. In this paper we
focus on environmental loads such as emissions and natural resource depletion.
There is a discussion about policies to promote investments in alternative fuel vehicles. For
example, a feebate system is suggested to encourage a fast introduction of electrical vehicles and
it seems possible to manage such a temporal shift of capital between different years (Ford). The
example below deals with some of these aspects and is a comparison between a Volvo
Environment Concept Truck and a conventional FL6, focusing on engine and transmission.
Figure 2 Environmental concept truck (ECT) Figure 3. FL6 truck
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‘The ECT is a hybrid vehicle with a gas turbine for charging a nickel-metal hydride battery pack.
‘The FL6 is a conventional truck, General data are shown in table 1.
ECT FL6
Loading capacity 15 ton 18 ton
i Power 142/94 kW 132 - 184 kW
i Torque 2850 Nm 550 - 825 Nm
| Power source EthanoVelectricity Diesel
1 Main material Aluminum Cast iron/Steel
i Driveline Gas turbine/NiMH-batteries Conventional diesel
‘ Nitrogen oxides 0.5 g/kWh 6.3 g/kWh
| Zero emission range 25 km 0
Table 1 General technical truck data
‘The life cycle impact value of emissions and resource use of the ECT and FL6 trucks has been
evaluated by means of the EPS system. The main result are shown in fig. 4.
Environmental load (kKELU)
180
160 [Break even area 2
120 Cy, oa / |
100 } [Break even area 1
0 200 400 600 300 1000
Distance (thousand km)
Figure 4, Accumulated environmental load as a function of driving distance, if assuming battery
replacement every 100 000 km and recycling of batteries.
The truck life cycle assessment deals with the environmental load per transported quantity and
distance (e.g. load/tonkm). In this case, both truck alternatives have approximately the same
Joading capacity and consequently we can focus on an assessment in relation to distance covered.
The possible total operational distance is quite similar for the two alternatives, but for both
alternatives the useful life is dependent on e.g. maintenance and financial considerations.
Consequently, it is instructive to study a graph of environmental load as a function of distance.
The direct and indirect load that is caused by primary production and is larger for the ECT than
for the FL6, because of higher resource values for rare metals used in batteries and electronics.
Direct and indirect effects from the truck usage phase are mainly due to emissions and fuel
consumption. The ECT also has a considerable environmental load for battery exchanges, which
has been assumed to occur every 100,000 km. Finally there is a waste management load and a
residual material. Many of today’s residuals are negative for human sustainability, but for some
interesting materials the residual is a recycling resource that enables a saving in future
environmental load, i.e. a positive effect for human sustainability in the environment. To a large
extent the trucks consists of metals for which there is a considerable load saving by recycling.
Consequently, the recovery of the truck material has a positive effect on the human resource
situation.
The figure 4 accumulated impact lines show a break even at approximately 700,000 km (break
even area 2). At a closer look this is a biased view, because the positive recycling value is larger
for the ECT. Provided that the recycling is done and that there is a true demand for the materials
at that point of time it is more relevant to make the comparison for the dotted lines, where the
end of life load saving has been-subtracted. In this view it becomes clear that the break even
happens at about 200,000 km. The transformation of view, from bold to dotted lines, means
quite a difference in the perception of the environmental characteristics relation between the two
vehicles. The difference between the two comparisons is that the bold lines perspective
disregards the difference in future environmental load, whereas the dotted line perspective takes
the total life cycle into consideration, as a basis for how the environmental comparison of the
trucks varies with the usage distance. This last perspective seems to show a more readily
understandable picture of the relation between the actual total life cycle loads (Karlsson 1995).
—
Validity assessment
One of the most important aspects of an environmental assessment is to clarify its validity,
uncertainty and sensitivity. At a basic level this applies for all forms of decision support, and it is
very important in multidimensional analyses, for example in environmentally related
comparisons of product life cycles. It is hardly possible to calculate readily understandable
environmental values, such as the ELU indices, that are very precise and unobjectionable. What
one can do is to assess and keep track of the uncertainty. The EPS system contains such tools.
The uncertainty in the priority given by the analysis is calculated by using estimations of
uncertainties in al] input data and using a Monte Carlo method. The results are shown in figure 5.
The diagram shows an 80% probability that the ECT is environmentally preferable. It also shows
that there is a 20% probability that the FL6 is better than the ECT. This result may appear to be
very unclear, and it may seem to be quite frustrating as decision support. However, we think that,
this illustrates a rather common phenomena in decision making about complex systems. The
uncertainty is there and Figure 5 is only a visualisation of what decision makers often have to
live with.
Environmental load,
FL6 - ECT (k ELU)
2500 L
2000 LL
1500 LL
T 20 30 40 50 60 70 80 90
Probability in % that the difference in environmental load
value is less than the value given at the Y-axis
Figure 5 Probability distribution for the difference in load between FL6 and ECT
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i
Continuous learning
One EPS system primary objective is to tell designers which one of two different concepts that is
least impacting on the environment and to find ways of decreasing a products environmental
impact through its life cycle. By inclusion of a recycling model the system facilitates sustainable
product development that to an increasing degree focuses more on materials, and not only on
specific products. The material indices facilitates a systems thinking based dialogue about where
high leverage actions may be found. From a quick primary calculation of the overall impact value
for a product using general impact indices for material production, maintenance, material
recycling, depositing, composting, incineration etc. the product environmental impact assessment
can be gradually refined as the information grows during the product development process.
The above comparison shows a clear environmental advantage for the ECT compared to the FL6.
Other EPS based evaluation can be used to show how the environmental characteristics for the
FL6 can be improved considerably, for example by a change to ethanol or aluminum. But, still the
ECT has a zero emission advantage by use of batteries. Furthermore, the basic reason for Volvo’s
work with this environmental concept car is not that exactly this design is thought to be the
absolute optimum. The reason for this project is to stimulate the continuous learning and thinking
about new possibilities.
The EPS methodology enables conceptualization of environmental relations and their
specification as explicit values, trends and validity clarifications. It is designed primarily as a
decision support tool for product design etc. In Volvo's experience, its main long-term advantage
is that the explicit specification of environmental characteristics serves as a priority guidance for
additional environmental analyses and as a foundation for dialogue and thereby further
clarification. This form of interrelation between cumulative learning and continuous
effectiveness improvements is discussed in (Karlsson 1997).
Conclusion
One main project conclusion is that the EPS system facilitates continuous learning through more
explicit dialogue about the relation between the own product system and its surrounding systems,
based on an environmental frame of reference.
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Environmental assessments does not produce absolute truths. What we can do is to specify more
explicit environmental relations, values and trends for the evaluated systems. In this way we get
a platform for further assessment and discussion of various aspects. The above ECT assessment
exemplifies how EPS is used as a basis to describe a readily comprehensible view of product life
cycle loads and to clarify the validity of an environmental product comparison. Such illustrations
have been found useful as systemic clarifications in Volvos continuous development of new
vehicle concepts and this observation about industrial learning is in agreement with our general
experience from the Product Ecology Project.
Acknowledgments
The support from the Swedish National Board for Industrial and Technical Development and the
Swedish Waste Research Council is gratefully acknowledged. The case is based on work by
David de Val and Jens Wiksell at Volvo.
References
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Protection Agency, Stockholm, Sweden
Karlsson Reine, Jamal Nassir, Pushkaraj P. Dandekar. 1997. Sustainable Business Development,
an attempt to get out of the environmental resource paradox, submitted to System Dynamics
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Steen, Bengt. EPS-Default valuation of environmental impacts from emissions and use of
resources. Version 1996.. Swedish Environmental Protection Agency, Report AFR-111. 1996.
ISO 14040 Environmental Management - Life cycle assessment - Principles and framework.
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