Comprehensive Evaluation of the Integrated Operational Capability of the Former General Electric Power Companies in Japan Based on Entropy-TOPSIS–Coupling Coordination–Grey Correlation Degree

The Former General Electric Utility in Japan is a major participant in the electricity market. The integrated operational capabilities of these power companies have significant impacts on the stable development and sustainability of the power industry. This study evaluates the comprehensive operational capabilities of these power companies from 2003 to 2015 and analyzes the indicators that may affect their operational capabilities. Establishing an evaluation index system comprising five subsystems, namely profitability, management, solvency, growth, and scale, and optimizing it using principal component analysis. The Technique for Order of Preference by Similarity to Ideal Solution was utilized to calculate the relative closeness of each company, with a score representing the integrated operational capabilities. Furthermore, coupling coordination and grey correlation analyses were conducted to assess the internal coordination among subsystems and to identify critical drivers of sustainable performance. The results show that (1) the Kyushu Electric Power Company and Tohoku Electric Power Company have strong integrated operational capabilities. (2) The five evaluation subsystems of integrated operational capability during the period of 2003–2015, fluctuated between moderate and high levels. (3) The top 5 indicators with the highest average grey correlation are as follows: “Hydropower capacity factor”, “Operating cash flow to current liabilities ratio”, “Operating profit growth rate”, “Net profit growth rate”, “Total capital utilization”. This study contributes to the sustainable management of the electricity industry by providing a systematic and data-driven assessment framework. The findings offer practical insights for optimizing corporate governance, enhancing energy efficiency, and formulating policy measures that support the long-term sustainability and competitiveness of Japan’s power utilities.