To create a new product system, what is a valid reference product output or waste input of a process?

Question

When I try to create a new product system for a process, I get the message "No process with valid reference product output or waste input selected".

My reference flow is a waste input, which I want to use as the functional unit. I have marked it "Avoided waste" and connected it to a process provider.

What could be the reason for why it is not valid?

Answer 1

Hi Maja,

an avoided waste is just as an avoided product removed from the system you are modeling and calculating ("system expansion, in LCA terminology, as alternative to allocation, when dealing with multi-functional processes), which means it does not exist any more in your system, and thus cannot be used as reference. You should remove the check at avoided waste and you should have another product or waste in your process, make this "avoided" instead.

Hth, Andreas

- it is typically easier if you add a screenshot of your process but I hope I understood how you modeled it..