This article addresses the emergence of Industrial Ecosystems, highlighting the HORSE Aveiro initiative to establish one in the Aveiro district. The objectives include investigating the strategic formulation process and developing the underlying business model. The adopted methodology involves literature review, an interview with the manager of a French Ecosystem, and in-depth strategic analysis, validated with local major companies and the Chamber of Commerce. The article results in the formulation of a strategy and business model, along with the involvement of large companies in the development of the Industrial Ecosystem in the Aveiro district. This provides a significant practical and methodological contribution for the development of other ecosystems.