How long does it last?
The Longevity criterion examines how long your product remains functional and valued in use, and whether its design supports repair, maintenance, and upgrade to extend that useful life.
A strong answer demonstrates that the product is designed for durability: using materials that withstand the conditions of use, making components that wear out accessible for replacement, and providing maintenance guidance that enables users to extend the product’s life. It also considers emotional longevity: whether the product will remain relevant and valued over time, not just functionally intact. A weak answer treats longevity as a quality issue rather than a design choice, or prioritises a low initial cost at the expense of lifespan.
Longevity is one of the most powerful levers for reducing a product’s environmental impact: a product that lasts twice as long, at the same level of material and energy input, halves the resource consumption per year of service. Design choices that extend life, such as modularity, repairability, and material quality, typically deliver environmental and commercial benefits simultaneously.
