FEAST, an ongoing study of the role of feedback in the software process, was prompted by various factors including the need to identify the mechanisms underpinning observed phenomena in a series of metrics-based studies of evolving software systems conducted during the seventies and eighties. Evidence to date indicates that feedback loop mechanisms play a significant role in determining the performance and dynamics of software processes. To improve understanding of the evolutionary behaviour of software systems and to exploit feedback in the context of process improvement it is necessary to improve knowledge of the origin and sources of feedback phenomena. This is also a prerequisite for a systematic definition of control and policy mechanisms for the management of such processes. This paper refers to some of the many dimensions that appear to relate to the issue of feedback in the global software process. It is argued that empirically assessing and modelling the presence and importance of those different dimensions in industrial software processes can bring significant progress to the FEAST investigation.