Peeping into the SAP R/3 System

Print Friendly

In this post I will be taking you into a sap R/3 system, explain you the process happening inside a SAP system. What happens between the process of pressing F8 (execute) and the displaying of result in o/p screen? Ever wondered of the operations happening inside….

There are three layers in a SAP R/3 system (3-tier architecture).

1)      Presentation Layer.

2)      Application Layer.

3)      Database Layer.

SAP R/3 Architecture


Coming into your Presentation layer, it’s nothing but your O/P screen.  Application layer is where all the logical operations take place. Database layer is where all the data is stored.

Application Layer consists of application servers (1 or more) and a message server. It also contains the work process for execution of user request.

Now coming to the working part.

As soon as you press F8 or execute a program a request is sent to the application layer. There will many requests coming to the application layer. It follows the FIFO (First in First Out) principle in considering the Request.

For executing a request a Work process is required. Application layer consists of many work processes under an application server. This process of assigning a work process based on availability is done by the Dispatcher. Following the FIFO principle, your request will be assigned a work process.

The work of message server is for load balancing. If there is multiple application servers, the message server communicate between them and assigns work simultaneously to different servers and hence reducing the load.

F8  ----------> Application layer ---------> Dispatcher ---------> Work Process (based on FIFO principle) ---------> here the work process does the work of fetching data from database layer (if required), calculations and other stuff  ---------> O/p is sent to the presentation layer.

Application layer does a two way communication with database layer as well as with the presentation layer.


Hi Ppl...this is LIPIN.... *i have nothing to talk about myself and i cant be talking abt myself either...sounds so dumb... hehe..!! :P * few things i believe in: "LiFe is too short to wake up in the morning with regrets so love the ppl who treat u right and forget the ones that dont and believe that everything happens 4 a reason....If u get a chance take it..if it changes ur life,let it..!!! nobody said it would be easy, they just promised it would be WORTH IT...!! " " LiFe is about trusting ur feelings and taking chances,loosing and finding happiness...appreciating the memories and learning from the past and realising people 'always change'..." "Being happy doesn't mean that everything is perfect..it means tat u have decided to live life despite its imperfections. So be happy because life sucks and ur doing just fine...!! "
More about

2 thoughts on “Peeping into the SAP R/3 System

Comment author said

By Davy Pelssers on 21 September 2012 at 13:52

Hi Lipin,
great to see your First Article online.

Keep up the good work - love to see more posts!
davy pelssers


Comment author said

By lipin on 22 September 2012 at 06:46

Thanks a lot Davy, That was encouraging.


Leave a Reply