zero values in most impact categories for Monte Carlo

Question

Hello ,

I'm doing a LCA for some process i created. i have no problem running the process in various impact assessments with consistant results. But when i try to run a Monte carlo sorting, i have strange results : The sorting runs normally on the inventory but when it comes to impact assessments, only some categories get non-zero values, the other being systematically 0.

To spice up this weird results, the categories that are systematically zero can change from one process to an other.

I don't know why i get this error because i set up the uncertainty on every flow. If you have any clue of what is happening, i will gladly discuss it with you !

Thank you !

Comments

Actually, it's related to the impact categories <strong>directly </strong>impacted by the inputs and outputs of the process. What i find is that uncertainty calculation cannot go upstream with Unit processes. is this standard behaviour or can i find a way to correct it?