<p>This paper addresses a critical gap in the energy sector by developing and empirically validating an integrated, value-based performance excellence model tailored for national electricity supply chains. While existing research often treats organizational capability, strategic focus, and sustainability in isolation, this study synthesizes these dimensions into a unified framework. Employing a mixed-method approach, we first utilize thematic analysis on data from 36 industry experts to extract seven core organizational capability indicators. Subsequently, a structural equation model, based on data from 294 managers across Iran’s generation, transmission, and distribution sectors, is used to test the relationships among organizational capability, organizational focus, and sustainable development. The findings reveal that organizational capability exerts a substantial positive influence on both organizational focus (β = 0.786) and sustainable development, with a combined total effect of β = 0.799. The model’s robustness is further validated through multi-group analysis, which uncovers the significant moderating role of the industry sub-sector in the capability-sustainability link. This research contributes a novel, empirically grounded framework that demonstrates how organizational strengths are systematically converted into sustainable value, offering a strategic roadmap for policymakers and energy executives.</p>