What is SAP R/3 ?

SAP R/3

SAP R/3 refers to Systems, Applications and Products for data Processing Real Time having a 3-tier Architecture. (Presentation, Application, Database Layers).

SAP is the leading ERP Software Solution Provider.

Releases

• SAP R/3 Release 1.0A Release Date 6 July 1992
• SAP R/3 Release 2.0 / 2.1 Released 1993
• SAP R/3 Release 3.0 / 3.1 Released 1995
• SAP R/3 Release 4.0B Release Date June 1998
• SAP R/3 Release 4.5B Release Date March 1999
• SAP R/3 Release 4.6A Release Date 1999
• SAP R/3 Release 4.6B Release Date Dec 1999
• SAP R/3 Release 4.6C Release Date April 2001
• SAP R/3 Enterprise Release 4.70 Release Date March- Dec 2003
• SAP R/3 Enterprise Edition 4.7
• SAP R/3 Enterprise Central Component 5.0
• SAP R/3 Enterprise Central Component 6.0

 

Architecture

SAP based the architecture of R/3 on a three-tier client/server

1. Presentation Layer(GUI)
2. Application Layer
3. Database Layer

Presentation Layer

The presentation layer contains the software components that make up the SAPgui (graphical user interface). This layer is the interface between the R/3 System and its users. The R/3 System uses the SAPgui to provide an intuitive graphical user interface for entering and displaying data.

The presentation layer sends the user’s input to the application server, and receives data for display from it. While a SAPgui component is running, it remains linked to a user’s terminal session in the R/3 System.

This software-oriented view can be expanded to include further layers, such as an Internet.

Application Layer

The application layer consists of one or more application servers and a message server. Each application server contains a set of services used to run the R/3 System. Theoretically, you only need one application server to run an R/3 System.

In practice, the services are distributed across more than one application server. This means that not all application servers will provide the full range of services. The message server is responsible for communication between the application servers. It passes requests from one application server to another within the system. It also contains information about application server groups and the current load balancing within them.

It uses this information to choose an appropriate server when a user logs onto the system.

Database Server

The database layer consists of a central database system containing all of the data in the R/3 System. The database system has two components - the database management system (DBMS), and the databse itself. 

SAP does not manufacture its own database. 

Instead, the R/3 System supports the following database systems from other suppliers: ADABAS D, DB2/400 (on AS/400), DB2/Common Server, DB2/MVS,INFORMIX, Microsoft SQL Server, ORACLE, and

ORACLE Parallel Server.

The database does not only contain the master data and transaction data from your business applications,all data for the entire R/3 System is stored there. 

For example, the database contains the control and Customizing data that determine how your R/3 System runs. It also contains the program code for your applications. Applications consist of program code, screen definitions, menus, function modules, and various other components. These are stored in a

special section of the database called the R/3 Repository, and are accordingly called Repository objects. You work with them in the ABAP Workbench.