[edit] History of SAP R/3

The first version of SAP's flagship enterprise software was a financial Accounting system named
R/1 called as YSR. This was replaced by R/2 at the end of the 1970s. SAP R/2 was in a
mainframe based business application software suite that was very successful in the 1980s and
early 1990s. It was particularly popular with large multinational European companies who
required soft-real-time business applications, with multi-currency and multi-language
capabilities built in. With the advent of distributed client–server computing SAP AG brought out
a client–server version of the software called SAP R/3 (The "R" was for "Real-time data
processing" and 3 was for 3-tier). This new architecture is compatible with multiple platforms
and operating systems, such as Microsoft Windows or UNIX. This opened up SAP to a whole
new customer base.

SAP R/3 was officially launched on 6 July 1992. It was renamed SAP ERP and later again
renamed ECC (ERP Central Component). SAP came to dominate the large business applications
market over the next 10 years. SAP ECC 5.0 ERP is the successor of SAP R/3 4.70. The newest
version of the suite is SAP ERP 6.0

[edit] Releases
 SAP R/3 Release 1.0A Release Date 6 July 1992
 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[2]
 SAP R/3 Enterprise Edition 4.7
 SAP R/3 Enterprise Central Component 5.0
 SAP R/3 Enterprise Central Component 6.0

[edit] Organization
SAP R/3 was arranged into distinct functional modules, covering the typical functions in place in
an organization. The most widely used modules were Financials and Controlling (FICO), Human
Resources (HR), Materials Management (MM), Sales & Distribution (SD), and Production
Planning (PP)[citation needed].

Each module handled specific business tasks on its own, but was linked to the others where
applicable. For instance, an invoice from the billing transaction of Sales & Distribution would
pass through to accounting, where it will appear in accounts receivable and cost of goods sold.

SAP typically focused on best practice methodologies for driving its software processes, but
more recently expanded into vertical markets. In these situations, SAP produced specialized
modules (referred to as IS or Industry Specific) geared toward a particular market segment, such
as utilities or retail.

[edit] Technology
SAP based the architecture of R/3 on a three-tier client/server

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

SAP allows the IT supported processing of a multitude of tasks, accruing in a typical company or
bank. SAP ERP is differing from R/3 mainly because it is based on SAP NetWeaver: core
components can be implemented in ABAP and in Java and new functional areas are mostly no
longer created as part of the previous ERP system, with closely interconnected constituents, but
as self-contained components or even systems.

[edit] Presentation Server

The presentation server is actually a program named sapgui.exe. It is usually installed on a user's
workstation. To start it, the user double-clicks on an icon on the desktop or chooses a menu path.
When started, the presentation server displays the R/3 menus within a window. This window is
commonly known as the SAPGUI, or the user interface (or simply, the interface). The interface
accepts input from the user in the form of keystrokes, mouse-clicks, and function keys, and sends
these requests to the application server to be processed. The application server sends the results
back to the SAPGUI which then formats the output for display to the user.

[edit] Application Server

An application server is a collection of executables that collectively interpret the ABAP/4

(Advanced Business Application Programming / 4th Generation) programs and manage the input
and output for them. When an application server is started, these executables all start at the same
time. When an application server is stopped, they all shut down together. The number of
processes that start up when you bring up the application server is defined in a single
configuration file called the application server profile. Each application server has a profile that
specifies its characteristics when it starts up and while it is running. For example, an application
server profile specifies:

 Number of processes and their types

 Amount of memory each process may use
 Length of time a user is inactive before being automatically logged off.

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. Not practical, only one
application server is needed to run an R/3 system. But 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.

The application server exists to interpret ABAP/4 programs, and they only run there-the
programs do not run on the presentation server. An ABAP/4 program can start an executable on
the presentation server, but an ABAP/4 program cannot execute there. If your ABAP/4 program
requests information from the database, the application server will format the request and send it
to the database server.cvb.

[edit] Database Server

The database server handles the user's request for addition, retrieval and modifications in the
data.

[edit] Security

Server-to-server communications can be encrypted with the SAP cryptographic library[3].

However, the SAP cryptographic library does not cover client-to-server encrypted
communications; an external technology covering Secure Network Communications and Secure
Socket Layer would have to be provided[4]

[edit] See also

 NetWeaver
 SAP ERP
 ABAP