how to change the reference process for a product system?

Question

Hi everyone,

I define all my unit processes (A,B,C,D) and in the end create the product system based on my last process(D). Therefore, in the resulting products system, the last process(D) is the reference process. However, I need to change it to another one(B). How may I do this?

Noting that if I create the product system based on B, only processes A and B are shown in the model graph.

Answer 1

Hello miladgoudarzi,

You can manage your product system via the input and output tab in each process.

To establish a process flow, the output of process A needs to be the input of process B, and the supplier must be selected as process A. That means that if you put the output flow of process C as an input to process B, you will get process B as the final process.

Be aware that you can not have a loop that goes A -> B -> C -> B, as the production of process B, requires the production of process B. This is a loop. Instead consider creating B1 and B2, where the loop can then go A -> B1 -> C -> B2.

I hope this was helpful, good luck.

Answer 2

Hi miladgoudarzi91,

not sure if I understood correctly but one way would be to make the product system for B and then connect flows of the processes of C and D in the model graph manually. Here can find how to search for recipients in the model graph: https://greendelta.github.io/openLCA2-manual/prod_sys/model_graph.html.
Best