| Worksheet W13 - Simplified Interpretation Method for LCA - Part 3 of LCA|
|Table of Contents|
|2. Putting into Practice|
|4. Software, templates and other support|
|5. Call on Resources|
|6. Literature, examples and background information|
The objective of the screening LCA is to gain:
- Recognition of the most relevant environmental aspects that could affect the sustainability performance of the product service system (PSS);
- Good knowledge of the characteristics, and to a certain extent the magnitude of the environmental impact caused by the product service system.
2.1 When and why should this tool be used?
This tool should be used during the PSS Idea Development phase in particular, and will help to orient the design towards sustainable options. The tool should be used after the design phase of the Exploring Opportunities phase. It should make use of the results obtained from Worksheet 3 – Inventory of Sustainability Indicators.
2.2 Who should use this tool?
The assessment experts (environmental and social experts).
3.1 How should this tool be used?
In case the decision timeline is short, the use of standard eco-indicators is useful. Such indicators reflect the total environmental load of commonly used materials and processes. A manual for designers, containing over 200 indicators is available free of charge http://www.pre.nl/eco-indicator99/default.htm; the annexe contains the standard list of indicators and simple tables.
The following steps must always be followed to ensure correct application of the Eco-indicator:
1. Establish the purpose of the Eco-indicator calculation;
2. Define the life cycle;
3. Quantify materials and processes;
4. Fill in the form;
5. Interpret the results.
In most cases it is recommended that you start simple and carry out a “rough” calculation in the first instance. Details can then be added and data can be revised or supplemented at a later stage. This ensures that you do not waste too much time with details.
Step 1 - Establish the purpose of the Eco-indicator calculation
Actions to be taken
· Define whether an analysis of one specific product is being carried out or a comparison between several PSS;
· Describe the PSS that is being analysed;
· Define the level of accuracy required.
If the purpose of the calculation is to obtain a rapid overall impression of a product’s major environmentally damaging processes, it is sufficient to include a number of core items.
This will result in approximate assumptions being made and only main processes being included. At a later stage, however, you may well wish to look specifically and in detail for alternatives to aspects of the problem or, for example, to compare a new design with an existing one. In that case a more meticulous approach is necessary and a solid, fair basis for comparison. It is also possible with comparisons to disregard components or processes that are common to both product life cycles.
Step 2 - Define the life cycle
Actions to be taken
· Draw up a schematic overview of the PSS life cycle. We recommend to use the System - Map for this (worksheet 15)
List the most important processes, materials and services. As you will see later, the indicator list of the Eco-Indicators 99 does not specify many services, so you will have to translate these in basic processes, such as energy, transport etc. The screening LCA using input output (worksheet 5A) can help you to get data on services.
Step 3 - Quantify materials, services and processes
Actions to be taken
· Determine a functional unit;
· Quantify all relevant processes from the process tree;
· Make assumptions for any missing data.
When you compare different PSS ideas generated, or when you compare PSS with a traditional product solution, you should try to define a comparison basis. Usually the main function is used as a basis, but many PSS have several functions, and quite often these are quite difficult to define in objective terms.
Step 4 - Fill in the form
Actions to be taken
· Note the materials and processes on the form and enter the amounts;
· Find the relevant Eco-indicator values and enter these;
· Calculate the scores by multiplying the amounts by the indicator values;
· Add the subsidiary results together.
A simple form has been developed to make the Eco-indicator calculations. Please refer to the template section to find this form. This sheet can be copied for personal use.
If an indicator value for a material or process is missing this causes a problem that can be resolved as follows:
· Check whether the missing indicator could make a significant contribution to the total environmental impact;
· Substitute a known indicator for the unknown one. If you study the list you will see that the indicator values for plastics are always in the same range. Based on this it is possible to estimate a value for a missing plastic that is within this range;
· Request an environmental expert to calculate a new indicator value. Software packages are available for this purpose.
The omission of a material or process because no indicator value is available is only admissible if it is clear that the anticipated contribution of this part is very small. It is generally better to estimate than to omit (A zero value is wrong anyhow).
Step 5 - Interpret the results
Actions to be taken
· Combine (provisional) conclusions with the results;
· Check the effect of assumptions and uncertainties;
· Amend conclusions (if appropriate);
· Check whether the purpose of the calculation has been met.
Analyse which processes and phases in the life cycle are the most important or which alternative has the lowest score. Always verify the effect of assumptions and uncertainties for these dominant processes.
Useful questions to keep in mind
· What happens to the result if an assumption changes slightly?
· Does the main conclusion stand or do the priorities or the preference for a product change? If so, the assumption will have to be reassessed, and supplementary information will have to be sought.
Please be aware of the fact that the standard Eco-indicator values from the list are not exact. In the Manual for Designers (see http://www.pre.nl/eco-indicator99/ei99-reports.htm) we discuss some of the reasons for this uncertainty and we suggest a procedure to deal with it.
The result should give you an estimate of the environmental load of the different products and services in the system. These results can also be fed as an input into to the tool on Sustainability Orienting Guidelines (Worksheet 18).
When PSS are compared it is also possible to understand which PSS alternative has a lower environmental load. Please be aware that this approach will provide only rough estimates. Therefore, you should only interpret significant differences (a factor 2 or more) as relevant.
ECO-indicators should not be used for external communication; it is not an eco-label.
3.3 Input needed/ data required/ data acquisition process
Good communication with suppliers and stakeholders that have participation in the value chain (use, disposal, distribution, etc).
This tool does not require any software, although you might want to try one of the following software tools, that contain the same indicators:
ECO-it, see www.pre.nl/eco-it
ECO-scan, see http://www.ind.tno.nl/en/product/ecoscan/index.html
4.2 Templates and other support
Notes on the process data
The last column of the indicator list contains a code, referring to the origin of the process data, like the emissions, extracted resources and land-uses. In Chapter 5 of the Manual for Designers we refer to this as the data collected under "Step 1".
Below the data sources are briefly described. In all cases the data has been entered into LCA software (SimaPro) and then evaluated with the Eco-indicator 99 methodology.
1.By far most data have been taken directly from the ESU-ETH database Ökoinventare für Energiesystemen (Environmental data on energy systems), the third edition, produced by ETH in Zurich. This very comprehensive database includes capital goods (i.e. concrete for hydroelectric dams and copper for the distribution of electricity) and items like exploration drilling (exploration drilling) for energy systems. Also for transport, capital goods and infrastructure (maintenance and construction of roads, railways and harbours) are included. For material production capital goods are not included. Finally it is important to note that land-use is taken into account in all processes.
2.The Swiss ministry of Environment (BUWAL) has developed a database on packaging materials with the above-mentioned ESU-ETH database as the starting point. However, in this database all capital goods are left out. For the Eco-indicator 99 project we used the data on waste disposal and a few specific packaging materials. For disposal data we made a number of recalculations to include the "positive" effects form reusing material (recycling) or energy (waste incineration). Next to this we used the [OECD 1997] compendium to generate waste scenarios for municipal and household waste for Europe. An important difference with the Eco-indicator 95 is that now we use European in stead of Dutch scenario data. [BUWAL 250-1998]
3.The European Plastics industry (APME) has collected state of the art data for average environmental load for many plastics. As far as possible we used the ESU-ETH version (see 1), as this combines the APME data with much better detailed energy and transport data. The data marked with a 3 are thus the original data, but as they use rather simplified energy and transport data, they can deviate approximately 10 % from the other indicators [APME/PWMI]
4.Processing data has mostly been taken form the Eco-indicator 95 project. In virtually all cases only the primary energy consumption has been taken into account. Material loss and additional materials as lubricants are not included. It should be noted that the energy consumption of a process is very much determined by the type of equipment, the geometry of a product and the scale of operation. Therefore we suggest to take these indicators only as a rough estimate and to calculate more specific data by determining the exact energy consumption in a particular case and to use the indicator for electricity consumption to find a better value. Experience shows that mechanical processing contributes relatively little to the environmental load over the lifecycle. This means the crude nature of the data does not really have to be a big problem. [Kemna 1982]
5.Data on alkyd paint production have been added on the basis of a somewhat older study of AKZO.
6.The KLM environmental annual report was the basis for the data on air transport. This data includes the handling of planes on the ground. [KLM 1999]
7.Data for recycling of plastics are taken from an extensive study of the Centre of Energy Conservation and Clean Technology [CE 1994]
5.1 Personnel and time needed
This process can be more or less time consuming, depending on the level details in which the analysis is carried out. It will require a few hours work, taking into consideration that data collection is time consuming.
6.1 Methodological References
Goedkoop, M.J.; Spriensma, R.S.; The Eco-indicator 99, Methodology report, A damage oriented LCIA Method; VROM Report, Den Haag, 1999