A consumption mix is a Determining product output from a Market activity. It represents the blended product that results when a market combines similar intermediate product outputs from multiple supplying activities and makes this mixture available to consuming activities within a product system.
In Life Cycle Assessment modelling, market activities serve a specific function: they represent the market mechanisms that aggregate products from various suppliers and distribute them to consumers. The consumption mix is the tangible result of this aggregation process. When multiple transforming activities produce similar or functionally equivalent products, a market activity collects these outputs and provides a single, mixed product stream that other activities can draw upon as an input.
As a determining product, the consumption mix has an important characteristic: changes in demand for it will directly affect the production volumes of the activities involved in its supply. This distinguishes it from by-products and reflects its role as a market-driven product output. The composition of a consumption mix depends on the market shares and production volumes of all the supplying activities that feed into the market activity.
The concept is essential for modelling realistic supply chains in LCA, where consumers typically do not source products from a single supplier but rather draw from a mixed market that reflects the weighted average of available suppliers. This market-based approach ensures that Life Cycle Inventory results account for the actual diversity of supply sources and their relative contributions to the products consumed within the system boundaries.
The consumption mix differs from a production mix in that it specifically represents the output available for consumption from a market activity, whereas production mix refers more broadly to the production-volume-weighted average of suppliers within a geographical area.
