This thesis differs from the technological perspective of SPI by identifying and analysing the organisational features of process improvement. A theoretical understanding is developed of how and why software process improvements occur and what are the consequences of the change process within a specific case. A packaged information systems organisation forms the basis for a substantive case study. Adding to the growing body of qualitative research, the study takes a critical hermeneutic perspective. In doing so it overcomes some of the criticisms of the interpretive studies especially the need for the research to be reflexive in nature. By looking at SPI as an emergent rather than deterministic activity, the design and action of the change process are shown to be intertwined and shaped by their context. This understanding is based upon a structurational perspective that highlights how the process improvements are enabled and constrained by their context. The work builds on the recent recognition that the improvements can be understood from an organisational learning perspective. Fresh insights to the improvement process are developed by recognising the role of the individual to facilitate or resist the improvement. The understanding gained here can be applied by organisations to enable them to improve the effectiveness of their SPI programmes, and so improve the quality of their software. Lessons are derived that show how software organisations can support the ongoing improvement through recognition of the learning and political aspects of the change by adopting an agile approach to SPI.