SAP R/3 System architecture

The SAP R/3 System architecture consists of three layers: Presentation, Application, and Data Storage. The
following diagram illustrates the function served by each layer and how the layers work together:

PRESENTATION
Desktop Management
Help desk
WAN Management
WAN Monitoring
MS-DOS
Windows
Macintosh
LAN WAN
UNIX
VMS
NT
UNIX
VMS
Parallel Server
Switch Over

Application
Automation
Workload Distribution
Workload Balancing
High Availability
Performance Tuning
Capacity Planing

DATA STORAGE
Recovery
Backup Strategy
Reorganization
High Availability
Performance & Tuning
Raid disks / Mirrored Disks / Network Backup
Hermes
Novell
OS/2

Presentation
This is where users of the SAP R/3 System will submit input to the SAP R/3 System for the processing of
business transactions. It is also where the output from these transactions appears as output fields, reports,
tables and spread sheets.
On the desktop level, R/3 offers a user-friendly graphical interface called SAPGUI. The system also
integrates alternative interfaces for optimum compliance with your requirements. This includes
integrating common PC applications. Information exchange is also carried out through the Internet, Kiosk
touch screen systems and telephone applications.

Application

An application is a logically independent component residing at the host operating system level within
the SAP R/3 client/server environment. This component is represented by an application server in the
SAP R/3 network. After a user initiates a request at the presentation level, logic is invoked to service and
process that information. The application logic modules can reside on one centralized host machine or be
distributed over several physical host machines within a particular SAP R/3 network.
Typically, the update and enqueue processes reside on the database server in the application layer. In
most cases, the message, spool and gateway processes will also reside on the database server. The
database server may also be referred to as the “central server”.
On the application level, R/3 offers sophisticated mechanisms to optimally use high-performance system
resources. The system implements interconnections between various applications so that they are practical
from a business perspective. R/3 closes the gap between the exacting concept of a business transaction
and transactions from a data processing perspective.

Data Storage

On the database level, R/3 exclusively uses relational database systems by various manufacturers. R/3 is
able to utilize the most advanced features of each database vendor’s product. In other words, it is not
constrained by the lack of features in any individual database engine. Instead, it is able to fully use a
supplier-specific implementation without jeopardizing it’s own portability.