Organizations are taking sustainability initiatives either voluntarily or to encounter pressures from their stakeholders. However, effectiveness of their actions has also been increasingly asked. This dissertation addresses this issue with the development of a conceptual sustainability performance assessment approach and a simulation platform to evaluate the holistic sustainability performance of organizations and their supply chain. Following a systematic approach, at first, main drivers for the adoption of sustainability initiatives were identified. Afterward, a consolidated list of sustainability performance indicators was developed by analyzing sustainability-related standards, guidelines, scientific literature, and secondary data sources published by industrial corporations. Based on the sustainability attribute categories and performance indicators, a framework for the holistic assessment of the sustainability performance of organizations and their supply chain was developed, and as well implemented by building an assessment tool named “Sustainometer”.