Calculation of product systems

In openLCA, impacts can be calculated only for product systems (and projects as comparisons of product systems). Processes are used within product systems, and not in itself available for impact calculation. It is however possible to create a product system with only one process and calculate the impacts then for this system.
If you want to analyse the impact assessment, first, the inventory of a product system needs to be calculated. To do so, open the product system by doubleclicking it, go to the tab „LCI results”, and calculate the inventory, if not done so before, by clicking on the equation symbol top right (see „Product system”). Save the inventory and then, in a next step, go to the next tab „LCIA results”. For obtaining the LCIA results, choose an impact assessment method and click on the calculation button.

If you click on you can export the results as an excel file.
By clicking on you can export earthster process contributions.

The chart

Under the tab „Chart” you can picture the processes or flows with the highest impacts to a certain impact category in a chart. Therefore, select an LCIA method and an impact category you want to consider. Now define the „top x”, choose processes or flows contribution, and click on „Draw chart”.

The colours in the chart represent the process contribution: red = high impact, orange-yellow = medium impact, green = little impact, and white = no impact.

The Sankey diagram

openLCA draws a Sankey diagram of the product system. This diagram is a graphical illustration of the impacts of different flows in the product system.

Below the diagram in the section „Properties” you can edit the Sankey diagram. You can make flows visible or hide them (click on „Visible” and select „True” or „False”), add a limiting value for the process contribution you want to picture (click on „More than x percent” and enter a value), and change the flow colours (click on „Color”, then click on and select one).

In the section „Properties” you can find several symbols:

pins this property view to the current selection

shows the different categories

shows advanced properties

restores default value

hides unlinked processes

unselects all

changes the layout