The objective of this chapter is to provide a detailed review of the core principles, foundations and issues of enterprise systems (ES). Since the late 1990s, enterprise systems have promised to seamlessly integrate information flowing through the organisation. They claim to lay redundant many of the integration problems associated with legacy systems. These promises are timely considering the current trends of globalization, virtual organisations, and constant business and technological changes, features of many strategy agendas. In an effort to better understand the nature of these packages this chapter reviews the ES evolutionary process, and generic software characteristics are also identified, followed by system benefits and limitations. A review of current approaches to ES implementation allows for a critique of system outcomes and identification of challenges facing today’s ES implementations. The chapter concludes with suggestions for overcoming some of these challenges.