Design for Environment
Using this Design for Environment (DfE) methodology results in calculated values on quantitative
environmental performance indicators (EPIs). Below is a stepwise description of the
working procedure divided into two parts. Part one describes how to establish
the basic prerequisites for the DfE work and part two describes how to execute
the method.
1. Establish a basis for the DfE work
To be able to use the method in design phases at different companies and
also in communication throughout the supply chain, common agreements need to
be made on some crucial concepts. These are the important bases for the DfE
method, and also the common language that will be used for communication of
environmental requirements and performance. The agreements have to be made in a
group consisting of representatives from all different companies and functions
who will be involved in the communication using this DfE-method. 1.1. Define a set of Environmental Performance Indicators (EPIs)
First a set of common EPIs has to be explicitly defined based on regulations,
company policy etc. EPIs are quantitative expression of the environmental
performance of the product you want to control. Each indicator has to be
explicitly defined either per sector or per company. Algorithms for how to
calculate each indicator has to be agreed and documented. This set of indicators will reflect
the requirements which the product has
to fulfill and at the same time measure the environmental impact.
Criteria of EPIs used in a DfE-system:
- They are measurable
- They are able to control and can be influenced by the DfE
process
- They address important and well defined environmental
issues
A definition of an EPI consists of a detailed description, algorithms and
defined inputs and outputs. A detailed description of EPIs and the EPI
definition process can be defined can be found
here. The calculations of the EPIs is based
on common material property data. The definition of the EPIs does hence also
involve the definition of the material properties that has to be acquired. See example of
material
property. Also the definition of other kinds of aspects which are
used in the EPI definitions, such as how to calculate weight, or the definition
of energy use, need to be agreed upon.
See example of a set of indicators:
The REPID set of indicators 2003
1.2. Develop a material list
All users of the DfE system have to use the same or compatible material lists,
since the calculation of the EPIs are based on the properties of these materials.
If many parties are included in the system they all need either to agree on a
common list or establish a translation between the different lists. A common
material list consists of construction materials used within the industry. If
incompatible material lists are used by different parts in the system, the
results from the calculations will not be comparable. See example of a
material list.
1.3. Acquire environmental data needed for the calculations of the EPIs
Material data needed for the calculations of the EPIs then have to be gathered,
documented and inserted into a common database. This should be performed in a
structured way including collection and investigation of available information
sources, finding the right data according to the material property definition
and data quality requirements, documentation of the data, and finally reviewing the acquired data.
Usage of a common data
format, such as the
ISO/TS 14048 Data documentation format, when
documenting the data is highly recommended.
1.4. Implement calculation functionality for the defined EPIs
To enable calculations of the EPIs the algorithms defined in 1.1 need to be
implemented as calculation functionality.
The calculations of the material related indicators are based on properties of
the materials in the analysed product. The calculation functionality aggregates
the commonly defined properties for these materials, in accordance with the
algorithms, into a score for each indicator. An indicator can
be calculated for any part in the component structure. See illustration of
calculation procedure.
2. Execution of the method
2.1. Specification of environmental requirements
The following work steps are performed by e.g. an environmental coordinator
using a tool (e.g. a spreadsheet) where the environmental requirements and targets
are defined for the product in terms of
the defined EPIs agreed on in 1.1.
- Create a DfE project with an environmental policy
Create a project that will keep all information regarding environmentally
related requirements (selection of EPIs and definition of target
values for each selected EPI) on the product together.
- Choose Environmental Performance Indicators (EPIs)
A set of EPIs for a certain product is chosen from the defined list. The chosen
EPIs should cover the whole life cycle of the product and be based on the same
calculation basis.
- Set target values for the EPIs
Target values for the chosen indicators should be set according to requirements
of the project.
2.2. Verify that a product design fulfils the requirements
The following work steps are performed in the product development process to
verify that a product design fulfils the requirements specified in 2.1. Some
kind of easy to use tool is needed to analyze the environmental
performance of products in terms of the defined EPIs based on the common material list, material property data for each material in the list, and
calculation functionality for each EPI.
- Insert product structure
Insert data on the product structure including a specification of which
materials and components the product is made of, and also other required
information as specified in the EPI definitions. The materials shall be
selected from (or translated to) the common material list. To reduce the
amount of work, the product structure should be imported from other systems
where it already has been inserted, such as a CAD- or PDM-system. Example of a
product structure.
- Calculate environmental performance indicators
Perform the calculation of the indicators for the product by using the
calculation functionality defined in 1.4. The calculations are
based on the material list and the material properties connected to these
materials.
- Improve or communicate the result and use it for decision-making
Compare the calculated EPI values with the targets. In case the product
fails to meet target - redesign and recalculate to see if target is reached.
This can be done iteratively within engineering design until all targets are
met.
The calculated EPI values can also be used to compare different alternative
designs to see which one of the alternatives that is best from an
environmental point of view.
Reports can also be generated with information about indicator results,
definitions of the indicators and also reports on how the calculations were
performed.
For complex products such as rail vehicles the indicators can be calculated
per part in the product structure in order to find out where the hot-spots are and where to focus
in order to improve environmental performance. One set of targets can be set on
product level and other targets for specific sub-components of the product.
For further
reading please see "Information material on REPID
software training session" (M. Erlandsson, K. Flemström, 2003).
Experiences
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