A market activity is an Activity that represents a market for a specific Product, serving as an intermediary node between production and consumption within Life Cycle Assessment system modelling. Unlike Transforming activities, which physically transform inputs into different outputs, market activities perform no physical transformation of the product itself.
The primary function of a market activity is to aggregate and mix similar intermediate product outputs from multiple supplying transforming activities. This aggregation process creates a representative average of available supply sources for a given product within a defined geographical area. The resulting output, known as a Consumption mix, reflects the weighted combination of all suppliers contributing to that market.
This consumption mix is then provided as an input to downstream transforming activities that require the product. By using market activities as intermediary nodes, LCA databases can more accurately model real-world supply chains, where consumers typically do not source products from a single supplier but rather from a market comprising multiple producers with varying production methods, technologies, and environmental profiles.
Market activities are particularly important in consequential LCA modelling, where understanding market dynamics, supplier substitution, and production volume constraints becomes essential for accurately modelling the consequences of changes in demand. The market activity framework enables practitioners to distinguish between the physical transformation processes (handled by transforming activities) and the economic distribution and allocation processes (handled by market activities).
In database architecture, market activities help avoid the need to directly link every consuming activity to every potential supplying activity, thereby simplifying system modelling whilst maintaining transparency about supply chain variability and uncertainty.
