Meaning of quantitative in quantitative reference for output flow

Question

Hello,

I am a beginner in OpenLCA and almost in LCA too...

I have read several things about the quantitative reference flows when defining a process but I still do not understand what is really the meaning of the word "quantitative".

Does it mean that this quantitative flow drives the other flows (inputs and/or outputs) as a multiplication factor ?

For example, in the case of an object manufacturing, if the value of the quantitative flow (object) is 2 items, will the other flows (resources and wastes from manufacturing) be taken into account twice in the calculation of the environmental impacts ?

Or do I have to set directly the values of the other flows considering the production of 2 items (i.e : 2 x resources and 2 x wastes) ?

Thank you in advance,

Thibaut

Answer 1

Hi Thibaut,

Welcome - the quantitative reference is the amount of the main product (or waste treated) of a process, and all other amounts are to be seen in relation to the amount of the quantitative reference. So, if the qr is 2 pieces of cars produced, all other inputs and outputs reflect that, so e.g. you have steel, cables, ... to produce two cars.

So, I have to set directly the values of the other flows considering the production of 2 items - yes exactly.

It is however a bit archaic because as of today, LCA processes are linear input / output systems, and thus any of the inputs or outputs could be selected as the quantitative reference, and be used to scale then the other input and outputs.

It is a useful convention to set the amount of the quantitative reference to 1, which makes comparison of different processes that are producing the same product easier.

Best wishes,

Andreas