This paper reviews how Open Access policies (OA) and Institutional Repositories (IR) might be portrayed as agents of change within the realm of scholarly publishing. Using commentary on academic publishing as background, commentary that sees OA and IR as optimal and inevitable, and beneficially disruptive of the existing system, two theoretical approaches are presented as ways of providing a more detailed and explicit analysis of OA/IR dynamics. Both theories to varying degrees derive their inspiration from an exploration of the nature of change. The first “disruptive technology/disruptive innovation” approach (Christensen) specifies change in market theory terms, a re-structuring "driven" by innovation within, and possibly disruptive of, existing market arrangements. The second approach views change as a process of "reassembling" and reconfiguring of relationships between elements of a network (Actor-Network Theory). The application of both approaches to OA/IR is explored, including reference to a case study on a university institutional repository implementation. While "disruption" and similar terms might be in common and casual use, the basic idea gains greater clarity in these theories, and in doing so promotes greater awareness of the assumptions being made, and the aspirations being pursued.