A transforming activity is an Activity that transforms inputs so that the product outputs of the activity are different from the inputs. This fundamental characteristic distinguishes transforming activities from Market activity types, which simply aggregate and distribute products without changing their fundamental nature.
The concept of transformation in Life Cycle Assessment extends beyond simple physical or chemical changes. A classic example illustrates this well: a hard coal mine is considered a transforming activity because it transforms hard coal in the ground (a natural resource) into marketable hard coal (a product). Even though the coal itself may appear chemically identical, the activity transforms its state from an unmined natural resource into an extracted, processed, and market-ready product. This transformation involves extraction, processing, and preparation activities that create value and change the product's availability and utility.
ISO 14040 and ISO 14044 define activities (referred to as processes in the standards) as the smallest elements in Life Cycle Inventory analysis for which input and output data are quantified. Transforming activities represent the core operational units within product systems, where materials, energy, and other inputs are converted into desired outputs through human or mechanical intervention.
Transforming activities encompass a wide range of activity types across product life cycles. These include extraction activities (mining, forestry, fishing), production activities (manufacturing, processing, assembly), transport activities (shipping, logistics, distribution), consumption activities (product use, service delivery), and treatment activities (waste management, recycling, disposal). Each of these activity categories involves genuine transformation of inputs into outputs with different characteristics, values, or utility.
The distinction between transforming activities and market activities is crucial for proper system modelling in LCA. Whilst transforming activities change the nature of what flows through them, market activities simply serve as aggregation points that mix similar products from multiple suppliers and distribute them to consumers without altering the products themselves.
