Difference in results

Question

Hello

I have a problem due to a big difference in results obtained by the same model.

In the file enclosed you can see the results one obtained by the model using Ecoinvent 3.12 (the higher results) and the lower one obtained using Ecoinvent 3.12 library.

I used the same method (IPCC 2021 ISO 14067) and the same allocation.

I create a new database and then I add the Ecoinvent 3.12 library created by a fresh Ecoinvent 3.12 one.

In the same database I import my model with its parameters and method and finally I perform calculation of product system.

Why there is the difference? Is something wrong in my flow?

Thank you

https://ask.openlca.org/?qa=blob&qa_blobid=9954992828345608931

Answer 1

Do you have no validation errors (right-click database "validate")? Are all your imported foreground processes correctly linked to the same provider from ecoinvent (please click "Check linking properties" and make sure that there is no processes without default provider set)? Is the required amount and the calculated inventory (the total elementary flow results) the same?

Comments

I worked and drilled the question and I find that in Ecoinvent 3.12 library downloaded from Nexsus and library created from Ecoinvent 3.12  database without modifications there are two strange things.
In processes in both libraries
market for used railway track | used railway track | Cutoff, U CH and
treatment of used railway track | used railway track | Cutoff, U
have in output two times the flow used railway track.
But in the same processes inside Ecoinvent database the flow "used railway track" appears in output only one time.
I corrected in the libraries and the result now differs only for 0,21% - in real world nothing.
I think it's the problem in creating Json file during library creation.