LCA step by step
This step by step
procedure is called the "Fast Track" method (making use of Excel
For the basics of LCA see tab Rigorous LCA.
Choice on the indicator.
When you have to make an LCA, the fisrt thing to do is to make a choice on which "single indicator" you will use.
At Delft University of Technology a choice between the lowwing 3 indicators is adviced:
o a "damage based" indicator: the recipe indicator (=the new ecoindicator '99) H/A (unit= Points)
o a single issue indicator: "global warming" only, the carbon footprint (unit= kg CO2 equivalent)
o a "prevention based" indicator: the eco-costs 2007 (unit= €)
o The carbon footprint is not suitable for cradle-to-cradle (recycling) analysis, since materials depletion is not incorporated in the indicator.
o The recipe indicator gives unsatisfactory results for combustion at the end of life in the Ecoinvent database. The results in the Idemat database are OK.
o For End of Life and C2C calculations, and for wood, the eco-costs give the most satisfactory results
There are two databases: Ecoinvent and Idemat. Ecoinvent contains
over 4500 LCIs. Idemat has over 1500 LCIs.See tab data. It is strongly advised
to look first in the Idemat list. When something is not available there, look
You will experience that the actual calculation is a matter of minutes, so you might consider to make your LCA in all the 3 single indicators, and find out whether or not your conclusion is influenced by the choice of the indicator system.
The 3 indicators are totally different in character. Therefore it is not possible to conclude that one system is better than the other (it is a matter of taste).
The Step by Step procedure
Step 1 Establish the aim and the goal of your analysis
o Is it a comparison of two products?
o Is it an attempt to improve the environmental characteristics of a typical design?
- less, or less harmful, materials?
- less energy in the use phase?
- less transport?
- better recycling or better incineration of waste for electricity?
- Cradle to Cradle solution?
- better durability?
Step 2 Establishment of "Functional Unit" and Boundary
o describe the function (system requirements) of your product or service
- Example for a coffee machine: 1000 cups of coffee per year (or: cups over the life time)
- Example for a transport system: 50 m3 freight over a distance of 300 km, no payload back
o make a drawing of your product system (from cradle to grave). See the example for a coffee machine
o determine the life time of the system components
o establish one or more transport scenarios (e.g. production in China or in Eastern Europe)
o establish the boundary limits (what do you include and what do you neglect in your system?
Step 3 Quantify materials, use of energy, etc. in your system
o collect (measure) data (e.g. weight, material, energy consumption)
o determine accuracy and relevance; establish allocation rules (or scenarios) and cut-off criteria
Step 4 Enter the data in an Excel calculation sheet (see for
an example of the calculation structure the
excel file of the coffe machine)
Data of ecoburden per kg (or other SI unit) are provided in the Excel files at tab data of this website.
If an indicator value for a material or process is missing this causes a missing indicator/material
problem that can be resolved as follows:
o check whether the missing indicator could make a significant contribution to the total environmental impact.
o substitute a known indicator for the unknown one
For example: If you study the list you will see that the indicator values for plastics are approximately in the same range; based on this, it is possible to estimate a value for a missing plastic that is within this range
o request an environmental expert to calculate a new indicator value in Simapro or Gabi.
o take the required energy for the process, calculate the eco-costs of it, and add the eco-costs of the extreme toxic emissions (if any).
It is generally better to estimate than to omit.
Step 5 Interpret the results and draw your conclusions
In this step you determine what can be improved (less pollution materials and processes). You make a comparison between alternatives.
A practical guide to LCA, for students, designers and business managers; Cradle-to-Grave and Cradle-to-Cradle, Joost G. Vogtländer, VSSD, Delft, 2010. See www.vssd.nl/hlf/b018.htm