SAP R/3 through version 4.6c consisted of various applications on top of SAP Basis, SAP's set of middleware programs and tools.
When SAP R/3 Enterprise was launched in 2002, all applications were built on top of the SAP Web Application Server. Extension sets were used to deliver new features and kept the core as stable as possible. The Web Application Server contained all the capabilities of SAP Basis.
As a result of marketing changes and changes in the industry, other versions of SAP have been released that address these changes. The first edition of mySAP ERP was launched in 2003 and bundled previously separate products, including SAP R/3 Enterprise, SAP Strategic Enterprise Management (SEM) and extension sets. The SAP Web Application Server was wrapped into NetWeaver, which was also introduced in 2003.
A complete architecture change took place with the introduction of mySAP ERP edition 2004. R/3 Enterprise was replaced with the introduction of ERP Central Component (SAP ECC). The SAP Business Warehouse, SAP Strategic Enterprise Management and Internet Transaction Server were also merged into SAP ECC, allowing users to run them under one instance. Architectural changes were also made to support an enterprise services architecture to transition customers to a services-oriented architecture.
Deployment and maintenance costs
SAP ERP systems effectively implemented can have cost benefits. Integration is the key in this process. "Generally, a company's level of data integration is highest when the company uses one vendor to supply all of its modules." An out-of-box software package has some level of integration but it depends on the expertise of the company to install the system and how the package allows the users to integrate the different modules.
It is estimated that "for a Fortune 500 company, software, hardware, and consulting costs can easily exceed $100 million (around $50 million to $500 million). Large companies can also spend $50 million to $100 million on upgrades. Full implementation of all modules can take years," which also adds to the end price. Midsized companies (fewer than 1,000 employees) are more likely to spend around $10 million to $20 million at most, and small companies are not likely to have the need for a fully integrated SAP ERP system unless they have the likelihood of becoming midsized and then the same data applies as would a midsized company. Independent studies have shown that deployment and maintenance costs of a SAP solution can greatly vary depending on the organization. For example, some point out that because of the rigid model proposed by the SAP tools, a lot of customization code to adapt to the business process may have to be developed and maintained. Some others pointed out that a return on investment could only be obtained when there was both a sufficient number of users and sufficient frequency of useDeploying SAP itself can also involve a lot of time and resources.