This document summarizes a research paper that analyzed factors affecting ERP system adoption and compared adoption between small-to-medium enterprises (SMEs) and large companies. The summary identifies that business complexity and organizational change were examined as factors potentially influencing ERP adoption. An empirical study of 366 companies found that business complexity was a weak predictor of adoption, while company size was a strong predictor. SMEs cited structural and organizational reasons for non-adoption more than financial constraints, differing from large companies who cited organizational reasons most.