It is often argued that inter-organisational systems (lOS) can increase organisational flexibility. A Continuous Replenishment Program (CRP) is an EDI-based lOS that aims to match product flow with consumer demand, yielding improvements in inventory management and logistics. Our aim is to understand not only how the use of CRP affects the complex notion of flexibility, but also how organisational and inter-organisational issues influence the impact of this technology. Flexibility is, thus, examined not only as a characteristic of an individual firm, but also as a property of the interaction between firms. Flexibility is also perceived as a dynamic characteristic changing over time, influenced by the organisational and interorganisational context. A case study of a grocery retail supply chain forms the basis of our research.