Longevity index for small electrical and electronic appliances: Qualitative assessment of reliability and durability

The growing concern over electronic waste and the need to extend product lifespans have highlighted longevity as a key aspect of sustainable product design. This research presents a longevity index as a practical tool for manufacturers and stakeholders to assess, communicate and improve the longevity of small electrical and electronic equipment (sEEE). The main novelty of the study lies in the integration of reliability and durability into a single operational index specifically developed for sEEE, combining technical, repairability, maintenance and warranty-related indicators through a transparent scoring and weighting system. The proposed methodology combines qualitative and quantitative elements to evaluate product longevity in a structured and comparable manner. The index was developed for application to different products within the sEEE category and implemented through an Excel-based tool that guides data collection and automatically calculates the final score. A controlled case-study application involving two products from the same category and three evaluators was conducted to examine the practical application of the method, its ability to differentiate between comparable products and inter-evaluator variability. A sensitivity analysis was also performed to assess the stability of the product scores and ranking under variations in the factor weights. As a decision-support tool, the longevity index contributes to circular economy objectives by providing structured information to support sustainable product choices.