Life cycle assessment is a standardized method for evaluating the environmental impacts of products, services, or systems across their entire life span. It considers stages from raw material extraction and manufacturing to use, maintenance, and end of life, including recycling or disposal. This cradle to grave perspective helps avoid burden shifting, where improvements in one stage create hidden impacts in another.

Central to life cycle assessment is the goal and scope definition, where the purpose, functional unit, and system boundaries are set. This is followed by life cycle inventory, which quantifies all relevant inputs and outputs, such as energy, materials, emissions, and waste flows. These data feed into life cycle impact assessment, where emissions and resource uses are translated into potential impacts on climate change, human health, ecosystems, and resource depletion. Finally, interpretation links results to decisions and identifies uncertainties and improvement options.

The method is codified in international standards and continues to evolve. Research addresses impact categories such as global warming, particulate matter formation, toxicity, water use, and land use, as well as regionalization and temporal dynamics. Special attention is paid to emerging technologies like renewable energy systems, batteries, and bio-based materials, where future performance and data quality are uncertain.

Life cycle assessment is used in industry, policy, and product design to compare alternatives, support eco-design, and underpin environmental labels. Current challenges include data gaps, methodological choices, and the integration of social and economic dimensions. Ongoing work focuses on better datasets, more transparent assumptions, and coupling with tools such as material flow analysis and environmental input output models.