openLCA archived user forum

Hello,

In creating my process, I had erroneously added an incorrect input flow (tap water), and want to remove it. However I get the message: "Cannot remove exchanges - One or more of the selected exchanges are used already in a product system and therefore cannot be deleted".

Because I don't want this input, I've simply written it's amount as "0" -- but it would be nice to remove it from my list, especially where it shows in the model graph.

Any ideas would be greatly appreciated.

Thanks,

Geoff

Sorry I am seeing this quite late - are you saying the exchange is not used elsewhere but you still cannot delete? No?
Thank you!
Andreas

Hi Andreas,

No problem. Here is the screenshot of this issue.

I personally had only added it once in my crop production process as an input, not adding it anywhere else. I wanted to characterize irrigation for the crop production process, but added the wrong water input. Then I couldn't delete it so just maintained it as a "0" input value. In the shot you can also see ALL of the other processes (aside from elementary flows) added as inputs.
Let me know if you have any ideas!

Thanks,

Geoff

Hi,

I am encountering exactly the same problem (can't delete an input) on openLCA 1.5 using ecoinvent 3.3.
Do you have an update on this issue ?
(It is quite annoying when all the product systems are created and you have to correct one thing)

Thanks,

Nicolas

Hi Nicolas,
interesting that you are now using openLCA - the message and check prevents incorrect product systems; you can check where the flow is used using a python script, or, via the user interface with "usage": Check in which processes the flow is used, and if it is only in one, check in which product system(s) the process is used, and edit it then in the model graph.
Note that in comparison to SimaPro which you are maybe more familiar with, openLCA allows you to connect the same process in various ways in life cycle models, without the workaround of setting parameters to 0 or similar efforts - which also works in openLCA, if you do not want to search for where the process is used, and edit it in the product systems.
Hope this helps,
Andreas

Hi Andreas,

Thank you for your answer.
I wonder if an automatic function could not be developped to remove a process when it is used by many product systems?
Python script will surely be the solution for me but for other people without basic programming skill it can be chronophage.

Nicolas

Thanks Nicolas - well indeed, but possibly, different modeling decisions are required in different product systems, which an automatic routine cannot probably solve automatically. But it should be possible, e.g. by guiding the user to these specific cases. If you are interested in sponsoring this, let us know ;)
Best
Andreas

Good morning. Iam also having a problem with removing exchanges in OpenLCA 1.6. Anyone who can help?
Tah

Hello and welcome,
basically the procedure is already described in the posts above, the exchange must not be used in any product system. We will try to make the procedure a bit less complicated in version 1.7.