Life cycle assessment (LCA)

An LCA starts by fixing two things that determine the whole answer: the functional unit (what the product does, like delivering 1,000 hours of light) and the system boundary, cradle-to-grave for the full life or cradle-to-gate when the study stops at the factory door. The team then builds a life cycle inventory of every material and energy flow, characterizes the impacts, and interprets the results. Two LCAs are only comparable when boundaries and functional units match, which is the first thing to check when a supplier hands you a flattering one. Environmental product declarations, increasingly requested in automotive and construction supply chains, are standardized summaries built on exactly this method.

The value for hardware teams is in trade-offs that intuition gets wrong. A lighter material can carry a dirtier production phase and still win on use-phase savings, or lose once end-of-life is counted, and an LCA is how you find out which. The results feed material selection, circular economy decisions like design for disassembly, and supplier requirements set through sustainable procurement. Keep the scopes straight: carbon accounting ledgers an organization's emissions year by year, a carbon footprint totals greenhouse gases for one product or entity, and an LCA examines a product across many impact categories at once.

Frequently asked questions

What is a life cycle assessment?

Life cycle assessment (LCA) quantifies the environmental impacts of a product across its entire life: raw material extraction, manufacturing, distribution, use, and end of life. Standardized by ISO 14040 and 14044, an LCA proceeds through goal and scope definition, inventory analysis, impact assessment, and interpretation, and covers multiple impact categories such as water use, acidification, and resource depletion.

What is the difference between an LCA and a carbon footprint?

A carbon footprint totals greenhouse gases for one product or entity, while an LCA examines a product across many impact categories at once, including water use, acidification, and resource depletion. Carbon accounting is different again: a ledger of an organization's emissions year by year. Keeping the three scopes straight prevents comparing numbers that measure different things.

What are functional units and system boundaries in an LCA?

An LCA starts by fixing the functional unit, meaning what the product does (such as delivering 1,000 hours of light), and the system boundary, cradle-to-grave for the full life or cradle-to-gate when the study stops at the factory door. Two LCAs are only comparable when boundaries and functional units match, which is the first thing to check when a supplier hands you a flattering one.

Why do LCA results sometimes flip depending on scope?

LCA results can reverse with boundary choice. In one study, a cradle-to-gate comparison favored a 2.8 kg steel bracket over a 1.7 kg aluminum one because aluminum production carries higher impacts per kilogram, but extending to cradle-to-grave on a high-mileage vehicle flipped the result once mass savings across 150,000 miles of use were counted. Trade-offs like this are where intuition gets materials questions wrong, and an LCA is how you find out.

How is LCA used in procurement?

LCA results feed material selection, circular economy decisions like design for disassembly, and supplier requirements set through sustainable procurement. Environmental product declarations, increasingly requested in automotive and construction supply chains, are standardized summaries built on the LCA method. The method also sets break-even rules: returnable totes beat single-use cardboard only after 30 round trips, so a four-year program at 48 trips justified returnables while a short pilot would not have.