MSI scores are the normalization of the impact assessment midpoints (LCIA results) for each impact category. Normalization factors for each impact category are created by adding the total impact of a weighted average of the most common finished materials used in apparel and footwear. This calculation results in the average amount of impact per impact category. This amount is then set as 10 MSI points (i.e. 10 MSI points is the average impact of a finished apparel/footwear material for that impact category). This amount (by impact category) is then used as the normalization factor to calculate the MSI scores of all processes and finished materials in the MSI. An MSI score of 5 points would mean a material has half the average impact of a finished apparel/footwear material in that impact category, while an MSI score of 20 points would mean the impact is double the average.
Note that MSI scores are only contextualizing the LCIA results. If one finished material’s global warming impact is lower than another, it is because the LCIA results are also lower. More information on the Normalization and weighted average can be found in the MSI methodology document on pages 12-13.