The holistic process sustainability index framework

Abstract

The world population now exceeds 8 billion people, and the demand for goods, energy, services, and food continues to grow. As large-scale processes meet these demands, sustainability becomes ever more vital for the long-term health of humans and the environment. To promote the most sustainable solutions in decision-making, there must be a means of comparing the sustainability of different processes. A quantitative measure of sustainability would allow for internal benchmarking, design assessment, and regulatory guidance. Therefore, the Holistic Process Sustainability Index (HPSI) framework is proposed, which provides a basis for translating the qualitative nature of sustainability into a quantitative form. This framework seeks to address the lack of process safety considerations in sustainability assessment and the lack of quantified connections between triple bottom line pillars. The foundation of this framework is established using an expanded triple bottom line: economics, environment, society, and safety are the key pillars. Indicators were then established to reflect the driving forces, pressures, states, exposures, and effects toward process sustainability. These indicators were analyzed using interpretive structural modeling to understand how indicators within one pillar of sustainability affect those from other pillars. The application of the framework was demonstrated through the development of the HPSI. Therefore, the proposed framework provides the basis for a dynamic sustainability metric that considers sustainability's economic, environmental, societal, and safety aspects while properly accounting for the interrelations between these different aspects.