This paper reports on research into how systems developers enact a systems development methodology (SDM) with a focus on describing how method enactment is bound up in everyday social and institutional structures. The case study develops the argument that institutional structures (such as authority, sets of norms and routine ways of doing things) embedded within the methodology are active forces in the systems development process. We ground our argument on the findings from a case study of an in-house developed SDM in a large-scale IT department within a major financial institution in Australia. The findings of the case show that despite the rhetoric of business client involvement working in unison with systems developers, the excerpts depict a conflict of interests with the client exercising nearly complete control over the development process and the in-house developers playing a submissive role. In terms of contribution to research, the study operationalises a theoretical framework that integrates elements of a social actor model outside its original domain to provide a deeper understanding of the institutional forces at play in information systems development.