Paradoxically, whilst historic Environment, Culture, Heritage, and Arts (ECHA) organisations curate knowledge for the public, thousands of them lack the required operational knowledge to manage their rapidly changeable and demanding operations. Their management requires extensive up-to-date knowledge, in accessible recorded formats (knowledge artefacts) interacting with human experience. For decades, the ECHA ecosystem, ECHAsystem [EE-kah-siss-tuhm], has been in a protracted crisis resulting in reduction of service for, and closures of, thousands of these organisations. The purpose of this cross-sectional, parallel mixed methods applied research was to develop a beneficial operational knowledge curating design to improve the ECHAsystem’s organisational sustainability. The findings demonstrated that accessible and up-to-date knowledge significantly improves processes and organisational sustainability performance. It also showed that a wise, allied development of knowledge resources, and allied application of available organisational resources, produces the greatest results. The research proposed the Athena [ah-thee-NAH] de-sign: a Knowledge Alliance coordinating the Operational Wisdom Library (OWL), in-formed by 31 networks across the ECHAsystem’s habitats and operations. The design can help individuals to grow professionally, organisations to thrive, and the ECHAsystem to achieve its aspirations. The research advocates a unified ECHAsystem benefiting from collaborative application of knowledge to deliver its public-good, intergenerational, organisational sustainability objectives.