Why don't I have a provider listed for my process inputs?

Question

When I select flows to input to my process, the dropdown menu under Provider does not have any options available to select. The same issue occurs when I create a product system and go to 'search providers for' on the right-click menu. This means I don't know how to add my unit processes for my inputs and therefore can't calculate anything. Any help would be appreciated. I only have access to free databases.

Comments

same situation, I know what product and waste flow mean, and I copy the output product flow of process A to next process, but I can't find the process A in the list of prodivers. Did you find out the reason why?thanks

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(difficult to say without picture, maybe you did not save the process that you want to see as provider?)

Answer 1

In openLCA you can connect product and waste flows of processes in a product system. When you have a process `A` that has an input of a product `b` and a process `B` that produces `b` as an output, you can connect this input of `b` in `A` with the output of `b` in `B`. Note that `b` needs to be a product flow (you select type = `Product flow` when you create that flow). For this example, you can then select `B` as the provider of the input of `b` in `A`.

For waste flows it is the other way around: you can connect the processes `A` and `W` when the process `A` has an output of waste flow `w` and the process `W` has `w` as an input. You can then select `W` as the default provider for the output of `w` in `A`. In openLCA, you cannot connect processes by elementary flows as these flows describe the direct exchanges of the processes with the environment related to the produced and consumed product and waste flows.