What is SAP and R/3?
SAP stands for system, application and product in data processing. It is one of the ERP soft wares which incorporates all the business functions into a single system by solving the data sharing problem between each department. The full name of the SAP is SAPAG, SAP is based in
1)MRP1-Material requirements planning
2)MRP2 –Manufacturing resource planning
The material requirements planning virtually evolves into manufacturing resources planning. Bills of materials are prime considerable point to estimate the requirement of raw materials in order to meet the demand of sales and distribution department, which is to be confirmed by sales order. The SAP family unites the organization from financials and Human resources to manufacturing and sales and distribution. It is also can be defined as integrated suite application which is divided into three co-functional areas.
1)Finanace
2)Human resource
3)Logistics
Again these 3 co-functional areas are divided into sub modules.
FINANCE
FINANCIALS
CONTROLLING
HR
PERSONNEL DEVELOPMENT
PERSONNEL MANAGEMENT
LOGISTICS
SALES AND DISTRIBUTION
MATERIAL MANAGEMENT
PRODUCTION PLANNING
INVENTORY MANAGEMENT
History of SAP
Way back to 1970s,four German Engineers ,the former employee of IBM, incorporated SAP AG and developed a new dimension ERP in order to give total business solution to the Industries which are having wide network in Global business.
SAP R/1 was first introduced in the world erp market.R/1 stands for real time data processing. By the end of the decade, intensive examination of SAP’s IBM database and dialog control system led to the birth of SAP R/2,designed to handle different languages and currencies. In 1990 they launched a new concept of client server architectural system.i,e R/3(Real time three tier architectural system)
It basically broke the conventional mainframe version and ushered into new era of technological advancement. When it was unleashed into the market, the client server architecture, the ability to maintain the consistency of data base and efficient data trafficking management system has placed it rank no1 among all other ERP soft wares.
The three tier architectural system consisted with Presentation layer, Application layer and Master database layer.
Presentation layer or server is nothing but a program code SAP GUI.EXE, which is installed in user workstation. Actual processing of the request doesn’t take place on the presentation layer .Presentation layer send the requests to application layer where the actual processing takes place. Presentation layer then receives the process information and formats the output according to the OS format.
Application layer
In this layer we have application server and message server. Application server is a set of executables which process the requests coming from the presentation layer.
The components of the Application Server are
Dispatcher
Dispatcher que
Work process
Roll area
User context
Message server is a virtual server which is used in the application layer to communicate between different AS.
Dispatcher
Dispatcher acts as an interface between the PS and AS. All the request coming from the PS are passed through dispatcher only. Dispatcher stores the request in the dispatcher queue. The dispatcher searches for the available free W.P. and assigns the request to the W.P after process is completed. Dispatcher again sends the processed output to the PS.
Dispatcher Queue
It is a storage area where the entire requests are stored by the dispatcher.
Work process: Work process is the main component of AS where actual processing of the request takes place.
There are different types of work process
ENQUE WORK PROCESS
BACKGROUD WORK PROCESS
SPOOL WORK PROCESS
UPDATE WORK PROCESS
DIALOG WORK PROCESS
GATEWAY WORK PROCESS
The components of the work process are
ABAP INERPRETER
Screen or dialog interpreter
Data base interpreter
Task handler
Work process internally assigns two buffer areas
Roll area
User content
Roll area
Roll area is used by the work process to store instance
Of a program.
User content
It is buffer area which is used by the work process to store information related to the user
Task handler
Task handler acts as a task manager which assigns request given by the dispatcher to the different interprets.
ABAP INTERPRETER
It is used to interpret the ABAP source code.
Screen Interpreter
It is used to interpret any screen change in the R/3 system. Attached to a screen there is flow logic and flow logic module. And these are called as dialog programs.
DATA BASE Server
In sap authorized system all the data related to the organization are stored in the form of tables. The tables are again physically stored in the data base. Database not only contains system related info but it also contains all the data required for an Organization.
Aditya Banerjee
