A persistent theme within supply chain management (SCM) research over the last fifteen years is that interfirm collaboration is an effective strategy towards achieving competitive advantage in supply chain relationships. This implies a degree of stability and openness operating in the chain. However, the observed corporate changes in a number of key Australian supply chains suggest that instability rather than stability is a consistent pattern in such relationsltips. This is particularly relevant when wider contextual impacts are considered. The Australian grains sector supply chains have experienced substantial change as a result of nticroeconontic reform, deregulation and the opportunistic nature of the participant stakeholders. While public policy has sought reform in key econontic sectors including land transport, the objectives and decisions argued witltin key policy and econontic principles have failed to deliver a sustainable outcome. Having an effective means of mapping the changing supply chain relationships offers analytical opportunities for the supply chain practitioners and policy makers.