A technology model is a conceptual model describing a procedure for linking Activity datasets to form Product systems. More broadly, it describes the process for transforming a Supply-use table into a Direct requirements table. The term is used synonymously with System model in Life Cycle Assessment.
In input-output economics, the technology model represents the fundamental assumptions and mathematical procedures used to allocate inputs and outputs amongst different activities when constructing economic models. These assumptions determine how the relationships between economic activities are represented and how flows of products and services are traced through the economy.
When applied to LCA, a technology model defines the rules and procedures for connecting individual activity datasets into complete product systems that model entire product life cycles. This includes decisions about how to handle multi-output activities, which production routes to include, and how to represent market dynamics. The choice of technology model has significant implications for LCA results, as different models embody different assumptions about how the economic and technical system responds to changes in demand.
The terminology varies across disciplines. Whilst "system model" is the preferred term in LCA practice, "technology model", "technology assumption", and "technology construct" are all synonyms commonly used in input-output economics literature to describe the same fundamental concept.
