Currently growing concerns about energy efficiency and sustainability across the manufacturing sector have spurred researchers to spend their efforts on improving energy efficiency. A recent study on sustainability assessment does not provide any real measurement linkages between energy matters and sustainability dimensions at the plant level. Simultaneously, a few papers that deal with technologies, not taking the sustainability associated with optimized energy intensity as a whole into account, still attempt to include LCA-based methods into the integrated sustainability methods. Thus, an energy-led approach for sustainability assessment is adopted using all-in-one methodology: SBM-DEA + energy LCA-LCC-SLCA. In accordance with the goal of the article, this approach will be performed by improving the energy efficiency of twelve production systems. This sustainability-oriented methodology is presented in the form of relative, aggregated sustainability indicators for production systems, I-ESUS, comparing quantitatively two scenarios: a baseline and a future scenario. The overall results in sustainability terms show, that improving the energy efficiency of production systems contributes significantly to energy sustainability. For the improvement scenario, the indicator amounts to I-ESUS = (2.565; 2.475; 2.264) compared with I-ESUS = (1.450; 2.937; 2.368) as baseline. This sustainable-oriented methodology will enable the implementation of a suitable performance measurement tool for supporting industrial energy policy-makers. If followed, the approach will allow for the improvement of energy-intensive manufacturer-dependent performance, guiding it towards energy sustainability. The robustness of the results is guaranteed by a sensitivity analysis.