<p>The service ecosystem concept is becoming an influential unit of analysis and set of assumptions describing a systemic, processual and institutional view of service and exchange. This thesis critiques this set of assumptions and the resulting construction of service ecosystems. The critique forms the first of a three-stage approach to metatheorising underpinning this thesis. At the core of this critique is the issue of conflation, which is aligned with the sociological frameworks and underlying assumptions informing this literature. Conflation collapses the multi-levelled and dimensional complexity of the structure of service ecosystems and leaves it devoid of its cumulative organising and effects played out across time. Following the critique, the thesis pursues two objectives. Firstly, a conceptualisation is developed which offers an overarching lens, connecting a critical realist and emergentist social ontology to an analytical framework and a process of theorising built on reconceptualising the constitution of service ecosystems. Secondly, the thesis undertakes an empirical study to actualise this lens, aiming to develop new theoretical insight and sources of explanation of how service ecosystems’ experience change and stability in developing through time. The thesis undertakes an embedded case study of ICT and digital reform in the New Zealand public sector and the enterprise services market, representing government agencies and service providers as a service ecosystem. The intensive case study provides an exploratory and illustrative setting in which to apply the metatheoretical and analytical framework and offers empirically informed mechanisms as theoretical propositions regarding the changing nature of the service ecosystem. The findings reveal four key mechanisms; compression, modes of alignment, ecotonal coupling and refraction. These mechanisms provide insight into the changing composition of the structure of the service ecosystem, the relationships of compatibility, tensions and complementarity between structures, the generative nature of emerging boundaries, and the role of history and layered organisation in shaping the trajectory of the service ecosystem. These mechanisms, informed by the overarching lens, contribute to overcoming conflation by establishing emergent relationality and a processual intertwining of being and becoming. These become the basis of multi-levelled, multi-dimensional complexity and cumulative organising. These foundations then allow the reconceptualising of change, coevolution and boundaries as important structural features. Finally, the under-theorised roles of stability and change, history, process, time and space are informed by these findings. Subsequently, this thesis contributes to: the need for further interconnected metatheoretical and midrange theoretical work investigating how service ecosystems adapt and evolve; the call to strengthen the metatheoretical and critical orientations and foundations of theories in marketing and service research; the critique of sociological frameworks and their theory-laden answers to the constitution of the social world and the terms on which it is to be researched and explained.</p>