`Process 1` is a multi-output process and you can define allocation factors related to the products `x` and `y` in `Process 1`. Say we have also an elementary flow `e` in `Process 1`:
We can allocate a fraction of the amount of `e` to each product `x` and `y` via allocation factors:
Now, when you calculate e.g. a product system with `Process 2A` which just takes `x` as an input:
you can select the allocation method in the calculation setup:
Depending which method you choose, the corresponding allocation factors are applied. For the example, `physical allocation` results in:
and `economic allocation` in:
Note that allocation factors are also applied to input product amounts so that you can allocate impacts of the supply chain too etc. The best is maybe just to try it out in openLCA. Also, in the next openLCA version it will be possible to use formulas for allocation factors so that you can bind allocation factors to product properties via parameters etc.