This article aims to understand and explain how eco-industrial parks can unfold over the traditional industrial production systems. Differentiating between the domain theory and method theory, we present an analytical framing that draws upon the strategic niche management perspective from the sustainability transitions field as the method theory, and then contribute to the field of industrial ecology, which is the domain theory behind eco-industrial development. With the experimentation concept being central to our conceptualisation, we consider the journey of the industrial production systems to become eco-industrial parks as niche experimentation and eco-industrial parks as niches. Employing a qualitative multiple case study, we analyse t...