Life cycle assessment (LCA)

What an LCA is, the ISO 14040 and 14044 standards, and the six stages.

Published on 10/08/2026

A life cycle assessment (LCA) measures a product's environmental footprint across its whole life, from the extraction of materials to the end of its use. It follows the ISO 14040 (principles and framework) and ISO 14044 (requirements and guidelines) standards.

Two key notions before starting

  • The functional unit: what the LCA measures, for example "a 40 mm steel watch case". All results relate to this unit, which is what makes comparison possible.
  • The system boundaries: what is included. A "cradle to gate" LCA stops at the workshop door; a "cradle to grave" LCA goes all the way to end of life.

The six life cycle stages

In CadranZero, a product LCA (a case, a dial, an assembled watch) is structured in six stages:

  1. Raw materials: metals, leather, sapphire, gold, with their masses and origins. Often the heaviest stage.
  2. Manufacturing: workshop energy, machining, surface treatments, material scrap rate.
  3. Transport: moving materials and components (road, air, sea); distances and modes matter a great deal.
  4. Distribution: packaging, cases, delivery to the customer house.
  5. Use: often negligible for a mechanical watch (no energy consumption).
  6. End of life: recycling, reuse or treatment of the materials.

From entry to result

Each stage receives entries (a material, a process, a transport leg), and each entry is linked to an emission factor (see the dedicated page). The stage total, then the product total, are calculated automatically.

An assembly can bring together several parts (and even other assemblies): their footprints roll up into the finished product's total. When you share a product with a house, its result feeds that house's Scope 3.1 (purchased goods and services).

Good practice

  • prefer primary data (your real masses, your real processes) over averages;
  • document your assumptions (material proxies, estimated distances): a transparent LCA is a credible LCA;
  • version your LCA as it evolves, to show an improvement path.

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