Sensitivity Analysis on Rainbow’s Refurbishing of Electronic Devices Methodology

This study conducted a sensitivity analysis on key parameters within the life cycle assessment (LCA) model of Rainbow’s Refurbishing of Electronic Devices methodology. Using verified data from twelve refurbishment projects covering six device types (smartphones, gaming consoles, laptops, PCs, tablets, and screens), the analysis identified which parameters most strongly influence greenhouse gas (GHG) emissions in baseline and project scenarios. Results showed that in the baseline scenario, the lifetime ratio between refurbished and new devices was the most influential parameter, with an average importance of 4,857,903 kg CO₂ eq, followed by market share of refurbished devices (mean μᵢ* of 302,318 kg CO₂ eq), while recycling shares were negligible (mean μᵢ* of 4,268 kg CO₂ eq). In the project scenario, residual value dominated for most devices, obtaining an average importance of 1,139,103 kg CO₂ eq for all device types. Full and light refurbishment shares also had strong influence (mean μᵢ* of 71,504 and 37,351 kg CO₂ eq, on average, respectively), with their ranges amplifying sensitivity, particularly for monitors. Transport parameters had device-specific effects: truck distance averaged 27,339 kg CO₂ eq in importance, whereas air distance reached 59,995 kg CO₂ eq, largely due to the wide range of distances and the high number of devices collected where it dominated. Finally, recycling shares were consistently the least influential project parameter (average μᵢ* of 10,910 kg CO₂ eq), reflecting their lower environmental footprint and narrower range. These results highlight the importance of accurate data on lifetimes, residual values, and refurbishment shares, while market shares, transport, and recycling parameters contribute comparatively lower uncertainty and therefore do not require the same level of precision.