Optional Elements, Weighting and Grouping

This lecture covers the evaluation of life cycle impacts, focusing on optional elements, weighting, and grouping. It explains the process of converting impact indicators into weighted scores based on value choices. Different weighting principles are discussed, including monetization, expert evaluation, and distance to target values. An example comparing the impact scores of popcorn and polystyrene is presented. The lecture also delves into the concept of grouping impact categories, detailing methods such as sorting and classification based on priority levels. The goal is to facilitate interpretation and decision-making, although these elements can be controversial and require sensitivity analysis.