openLCA analysis group vs EN15804 modularity principle

Question

Hello,

I have a question regarding EPD result output using the Analysis Group functionality. When modelling product losses (e.g. installation losses in step A5), I call the modelling of the previous steps (raw material, transport, etc. as shown in following screenshot) to account for the additional impacts.

I present below an example (openLCA 2.6.0, ecoinvent 3.11 EN15804 addon). Sorry for the poor quality of images, I hope it is understandable.

Modelling A1-A3: https://ask.openlca.org/?qa=blob&qa_blobid=7321254029807437747

Modelling A4: https://ask.openlca.org/?qa=blob&qa_blobid=4074706393265090502

Modelling A5: https://ask.openlca.org/?qa=blob&qa_blobid=6123911699734712441

Modelling A1-A5: https://ask.openlca.org/?qa=blob&qa_blobid=17544942298013758383

Product system A1-A5 model graph: https://ask.openlca.org/?qa=blob&qa_blobid=10886902451993321642

Results with no installation losses: https://ask.openlca.org/?qa=blob&qa_blobid=13633924740308009024

Results with 10% installation losses: https://ask.openlca.org/?qa=blob&qa_blobid=9773522814784336817

I get no impact in A5 when I have no losses. But I also get (almost) no impact in A5 when having 10% losses (A1-A3 and A4 are increased by 10% instead).

According to EN 15804 modularity principle (section 6.3.5.1), losses in step A5 must produce impacts only in step A5. The way I use it, Analysis Group functionality is not compliant with this principle of EN 15804:

"all environmental aspects and impacts are declared in the life cycle stage where they appear"

Is there a way around this?

Thanks in advance,

Jocelyn

Answer 1

Hello,

Can you post the screenshot ?

Comments

To model installation losses (A5), I have to repeat preceeding steps (A1-A4) in A5 due to modularity principle.

Answer 2

I am not sure what you mean by the modularity principle or how it relates to repeating preceding steps.

In any case, the analysis group works by avoiding double counting. For example, if you define analysis group A1, then all contributions attributable to A1 that are also included in A5 will be accounted for under A1 when you examine the results. This is why, when you change A5, the results behaves accordingly.

This is also explained toward the end of the following page: https://greendelta.github.io/openLCA2-manual/res_analysis/res_analysis_groups.html?highlight=analysis#new--analysis-groups
 

Therefore, in your case, since you are looping processes with one another, I recommend reading the results from the contribution tree.

Final recommendation: there was a bug in the analysis group feature that has now been fixed in openLCA 2.6. This issue was identified in a former question:https://ask.openlca.org/9846/specific-application-of-analysis-groups
 

Comments

Hello Ashrakat,
I have provided more details by updating my initial question.
I hope all is clear.
Thanks

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Hello
Following up on my second answer, I recommend you create product system out of each of your modules and insert them in a project to calculate them in a single shot

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Thank you Ashrakat,
I see that the solution of running in a project indeed resolves this issue or modularity. The drawback is then that you loose all functionalities of product system to analyse the results.
Please keep me posted in case the analysis group functionality is modified to align with EN15804 modularity principle.
Best regards,
Jocelyn