An activity class is a group of activities classified together under a heading in a statistical classification of activities. These classifications provide standardised frameworks for organising and categorising economic and industrial activities according to their nature, function, or sector. The most prominent example is ISIC, the International Standard Industrial Classification of All Economic Activities, which is maintained by the United Nations and used globally for statistical purposes.
Activity classes serve as essential tools for organising life cycle inventory data and enabling consistent aggregation and comparison of activities across different studies, databases, and geographical regions. By grouping similar activities together, these classifications facilitate the development of representative datasets that reflect average conditions or typical practices within specific sectors or industries.
In LCA databases, activity classes help structure data hierarchically, making it easier to identify relevant processes, conduct screening analyses, and ensure data consistency. They also support the creation of input-output models and hybrid LCA approaches by providing a common language that bridges process-specific data with broader economic statistics.
