Wednesday, 8 June 2016

Installation Steps


Installation Steps
Before starting SAP system it is highly recommended that you must download and read  sap installation guide from SAP Marketplace. 
 1.   Size your SAP system. Sizing is the process of deciding on the size of the system in terms of computing power, physical space needed, network infrastructure, and so forth. Size is a function of the number of users and which R/3 business modules they will work on, how large the database will be, and what the processing power or availability required to meet the system demands is.
   Sizing SAP systems is based on a unit known as the SAP Application Benchmark Performance Standard (SAPS). 100 SAPSs are equivalent to 2000 order line items processed in an hour (SD module) or 6000 dialog steps with 2000 postings in an hour (FI module).       
  To calculate the network bandwidth, customers have to know the number of sites and the number of users per site and per module. SAP hardware and technology partners can help in this process. A formula based on benchmark is available for an approximate sizing:

Where
C = required line capacity measured in bits/sec
N = number of users
L = line utilization (0 < L < 1). Values of line utilization higher than 50% are not recommended.
Tthinktime = think time between two dialog steps (average = 30 sec)
Tresponse = response time (average = 1 sec)
2. Decide on the installation type. This step answers the question, how will we implement the SAP R/3 client/server approach?
3. Check the installation requirements. R/3 will only install if certain minimum requirements are met.
4. Install and configure the hardware, base software, and network. Once we get our computer server, we have to get it up and running. You will at least need to install the server operating system, the additional required base software, and configure your network.
5. Installation preparations: adapt systems to SAP requirements. UNIX systems will require adapting some kernel parameters, swapping space, and sometimes installing additional software. Windows NT requires the installation of products such as the Microsoft Management Console (MMC), and adjustments in NT cache, paging space, NT domain, and other parameters.
6. Design the layout of file systems and set them up. Depending upon your system sizing and available resources, you have to design the best way to implement the required file systems.
7. Installation tool. SWPM is used to install sap software.
    The order of the following two points differs between UNIX and Windows NT systems. On UNIX systems, install the R/3 instances first and then the database system; in Windows NT, first install the database software and then the R/3 instances.
8. Install the SAP R/3 central instance. The R/3 central instance is the first piece of SAP software that the installation utility creates and configures. It automatically creates the SAP directory structure and a set of services (work processes) of all available types: dialog, background, update, spool, enqueue, message server, and gateway server.
9. Install the database system. This is the process of installing the underlying R/3 database program and creating the run-time and directory structure of the database according to user inputs.
10. Build and load the database. Once the database engine is installed from the previous step, the  installation utility creates the database structure, and allows you to insert the SAP default database data into the system. At this point, you could decide to import the data from another system (customer system).
11. Import ABAP program loads. At this point your SAP system is installed and almost ready for use. This installation step loads ABAP pregenerated programs, so that the system will not have to precompiled and generate them when they are first called. This is important for performance reasons.