A representative sample of 60 firms drawn from the Fortune 1000 that had recently adopted Enterprise Resource Planning (ERP) systems were used to test a model of weak appropriation with significant results. Leadership (social learning theory), Business process reengineering (change the company not the technology)and acquisition strategy (buy, don’t make), controlling for EDI (electronic data interchange), when the project was begun, industry (manufacturing versus service) and scale (sales) were found to be significant predictors of adoption performance. In general, strong, hands-on leadership, and business process re-engineering coupled with purchasing ERP systems was found to be a much more effective adaptation strategy than tailoring enterprise software.