Specific Application of Analysis Groups

Question

Dear community,

I have recently played around with Analysis Groups to investigate the hotspots of a separation process. It is modelled as a waste treatment process. 

I use openLCA 2.5.0 and ecoinvent cut-off UPR 3.11

As an input, I use Elecricity, water and steel. Here the steel represents the cutting edges, which are regularly changed. Because I have two cutting edge components, i originally have two inputs of the same material: 

You can also see the assigneg analysis groups. For this product system i get corrupted results for the analysis groups with a large rest.

However, if i adapt the process and sum up the steel inputs into one flow the results are caculated correctly.

My main motivation to post this is that I am seeking for a deeper understanding of the function "analysis groups". Can you explain to me why the results come out this way? Is there some documentation on the algorithm behind it? I personally love the functionality, but I dont really feel capable of correctly implementing it in a consistent manner. 

Thanks,

Paul

Answer 1

Hi Paul, from what you post, I do not see the analysis groups? Also, what do you mean by 

i get corrupted results for the analysis groups with a large rest

Your process is a waste treatment proces, and you have two times the same product inputs from the same process which is a bit a special case. I will check if the analysis groups cannot handle that, could be.

Thank you!

Andreas 

Comments

Hi Andreas,
thanks for your answer.
 I will edit the original post to show my analysis group calculations.

The analysis groups are also visible in the processes of the product system before the ::

By corrupted results I mean that there should not be any rest, because all processes are assigned to a analyisis group, however there is a large rest.

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thank you - so we checked and it is indeed a bug, linking the same process twice in a process does not work. We will fix this in a next release.

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Interesting - thank you for having a look!
cheers,
Paul

Answer 2

Answering your motivation, you can read more about it here: https://greendelta.github.io/openLCA2-manual/res_analysis/res_analysis_groups.html?highlight=anal#new--analysis-groups

Comments

Thanks for that - I read this already a few times - it is helpful but doesnt really explain how it works with complex product systems and loops :)