Allocation

Allocation is the way a shared input, such as a factory's electricity, is split between the different products made with it.

Most factories make many products, but their energy bills cover all of them. Allocation divides the total, for example by weight, by machine time or by value, so each product carries its share.

The method should match how the input is really used, and it should be the same across products, so that footprints from one factory can be read side by side.