This document discusses the evolution and implementation of enterprise resource planning (ERP) systems. It begins with an overview of what ERP systems are and how they work by integrating various business functions and databases into a single system. The document then discusses ERP implementation through a case study of Nestle USA's multi-year SAP implementation project. Key challenges, objectives, implementation issues, and benefits realized by Nestle are summarized. The document concludes with lessons learned from Nestle's ERP experience.