Enterprises rely more on Information Systems (IS) and software than ever before. However the issue of maintaining a vendor-supplied IS, in particular standard packaged software, has been poorly represented within academic literature. This paper presents a conceptual study that synthesises the current state of research concerning the deferral or execution of vendor-supplied maintenance by the purchasing organisation. Based on a systematic review process that adopts the purchaser’s viewpoint, a series of fears and triggers emerge and are captured from the literature. Fears are articulated as reasons for the purchasing organisation deferring the installation of vendor-supplied maintenance, whereas triggers are events that upset the equilibrium of the purchasing organisation’s IS or software and require the installation of the vendor-supplied maintenance to proceed. Although prevalent in literature, fears and triggers have not previously been recognised as an area of focus for academic research.