This chapter commences with a brief description of Enterprise Resource Planning (ERP), follows by a description of SAP, the largest enterprise software provider in the world. The timeline of activities since its inception in 1972 are summarized in a table. SAP’s flagship software program, the R/3 system, is portrayed in more detail. The capabilities of the R/3 system, the three-tier client/server technology it employs, its hardware and software, and several problems associated with its implementation and use are discussed. The two R/3 implementation tools – namely, the Accelerated SAP and the Ready to Run systems – are also described.