The complexities in making an enterprise resource planning (ERP) upgrade decision have been widely cited in the trade press. As a consequence, a significant percentage of ERP clients deferring the upgrade decision is resulted. Yet, to date we observe paucity of research with which to conceptualize and explain the important factors influencing ERP upgrade decision. This study attempts to explain the rationales behind the upgrade decision (regardless for short- or long-term) using the resource-based view (RBV). The hypotheses derived from the theoretical perspective are proposed and the research method is discussed.