Impact Result doesn't make sense

Question

Hi all, Lets say my product system (OSM Part) has two processes involved.

1. Milling (input : Aluminum sheet and electricity; output: Milled part)

2. Bending (input: Milled part and electricity; output: Finished part)

While creating the product system, I ticked the Auto-link processes option and selected unit processes since my boundary is cradle to gate. I kept the values as 1 unit for this trail calculation, but the impact result I got doesn't make sense at all (i mean the impact results are huge). I am attaching some screen shots of the processes and results. It would be really helpful if someone can point out what I might have done wrong.

I am using USLCI database and TRACI 2.1

Comments

Everything seems alright in your screenshot. Suspect that things may have gone wrong in the auto-connections happening in the USLCI electricity or aluminum. I would try checking to use only default providers (as opposed to prefer default providers). If using prefer default provider is chosen and no default provider is found, it will go find a process with a matching flow name.

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Thanks for your reply. But I tried them with 'only link default provider' as well and the result was pretty high for that option too. I am also assuming that something is wrong with the auto connection processes but I dont know how to find it or fix it

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Yeah, some of these can be super tough. For example I've seen weird results caused by a circular flow somewhere that was hard to see even with the model graph completely expanded. You might be able to look at analysis results -> inventory results -> total requirements to see if there's some really large product flow that might point to the process causing the bad result. With a result that high, my hope would be that something really jumps out.

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this is related to the old USLCI database that we have on Nexus - we are working on an update (basically providing the pdated data from LCACommons) - thank you for your patience.