Entwicklung einer Methodik für die Berechnung eines Nachhaltigkeitsindex für Unternehmen

This study develops and demonstrates a comparative assessment approach for companies’ ESG performance, based on Multi-Criteria Decision Analysis (MCDA) and Life Cycle Assessment (LCA). Based on the European Sustainability Reporting Standards (ESRS) and the Corporate Sustainability Reporting Directive (CSRD), 19 key performance indicators (KPIs) are defined, mapped to a common 0-10 scale and aggregated into a composite index. The three intensity KPIs for energy, emissions and water are evaluated per division using a distance-to-reference approach (i.e., to a benchmark) and are complemented by KPI-specific thresholds. Scope 2 emissions are assessed strictly location-based (standard); market-based values are not reported and serve only as a fallback. The reference framework for these KPIs is EU27_2020, with a base year of 2022. Each company is evaluated for its most recently published fiscal year. Missing company values are assigned zero points. If a KPI is missing for at least 80% of companies, it is marked as unavailable (“n. v.”) and excluded from the calculation. A KPI is only evaluated if at least 80% of firms in the division report it. Otherwise, it is treated division-wide as not available (“n. v.”). This means it is excluded from the aggregation and the weights are re-normalised across the available KPIs. If divisional reporting is at least 80%, missing company values are imputed as 0 and included.
Instead of using a single baseline index, performance is summarised using three sustainability values on a scale of 0 to 1: NA (additive; SAW), NI (ideal proximity; TOPSIS) and NK (compromise; VIKOR), reported as 1-Q. For each method, the equal weights (G), EWM (E) and CRITIC (C) are combined with α_G=α_E=α_C=1/3 to enhance robustness and prevent any single view from dominating. Optionally, a sustainability composite NG can be formed as a convex combination of NA, NI and NK (β=1/3). In a threshold test, the classification band edges are shifted by ±5 percentage points; any reclassifications are reported. KPI values and weights remain unchanged. The application covers five NACE divisions, each comprising three companies.
The results provide interpretable individual assessments and a stable core ranking that is consistent across methods and weighting variants. Rank switches are more frequent before α-bundling but rankings become more consistent and robust after aggregation to NA/NI/NK. The proposed calculation methodology for a sustainability index is characterised by regulatory alignment (ESRS/CSRD), transparent and reproducible computations, and a structured robustness analysis. The index prioritises benchmarking, internal management, and external communication.