This document discusses the history and evolution of organizational systems, from early calculation systems used in the 1950s-1980s to address single business functions, to later functional systems of the 1970s-1990s that began integrating some departmental systems. It then describes the development of enterprise resource planning (ERP) systems starting in the 1990s to integrate all business functions and processes across an entire organization onto a single computer system. Key benefits of ERP include integrated data sharing and real-time information across the enterprise. The document also notes some challenges of ERP implementation like whether to modify business processes or software.