Monte carlo simulation problem

Question

Hello

Why Monte Carlo simulation is not performed when in the LCA model there are some amounts set to zero?

I could have some situations where the amount is defined by formula and the result could be zero.

In these situations Monte Carlo starts but immediately ends without results.

Someone can explain how I can avoid this situation.

Thanks

Answer 1

This should not be the case. To help understand your issue further can you mention the database you are using and the data quality system (or how you set your uncertainty in your inputs/output process) ?

Comments

I posted the pictures you requested.

Answer 2

Here the process.

First picture you can see the formula

in this one you can see the results. Some data are zero due to the calculation. If I perform Monte Carlo analisys it does not work. If I remove zeros it works.

Comments

Hello Talon,
I tried to recreate your case and supposedly it works actually: I made an equation that yield a zero value and did a Monte Carlo simulation and it works. I am not quite sure why is that the case for you.

I would recommend you create a product system, then do your Monte Carlo simulation. Because the only time it did not work for me is when I did a direct calculation.

Else I would recommend you book a modeler support hour so we can investigate your issue further.

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I create a Product system but with zeros it does not work.
It's the same as I perform a direct calculation.
How can I book a modeler support? How much does it cost?

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You can book through here: https://nexus.openlca.org/service/openLCA%20Support%20(help%20desk)

I can also recommend you this manual chapter on uncertainity just to make sure you are not missing any steps:
https://greendelta.github.io/openLCA2-manual/advanced_top/monte_carlo.html?highlight=uncer#adding-uncertainty-information

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I did it.
The only problem is the amount set to zero, if there is one Monte Carlo does not work.
When I have amount different from zero it works.