SAP Sizing

Before SAP software is installed SAP environment must be planned.

The process of planning the environment is called "sizing".

Following decisions must be made:

§  How many installations would be there in the landscape (see next article).

§  How many application servers (middle tier) will be deployed to share the load.

§  What SAP components will be deployed.

§  How the components will be they deployed.

§  What would be the size of the database and hence the disk capacity of the database server.

§  How scalable the system needs to be (How fast the company will grow).

§  What would be the disaster recovery plan.

§  What should be the availability of the system. (Time when system is not down).

§  What kind of performance is acceptable especially when workload is high (month-end processes).

The above questions are answered by IT department working closely with SAP's implementation consultants (integrator) and the hardware partners.

The design process should start early.

Business should be engaged as quickly as possible to gather requirements.

Then SAP integrator and hardware partners should translate these requirements into sizing recommendations.

SAP Instances

An SAP environment consists of multiple SAP instances or installations.

Most common approach is to have three installations (also refer to as three-system landscape):

§  Development System - Used by developers to develop or modify the software.

§  Quality assurance or Test System - Used by testers to test the new development.

§  Production System - Used by users to run the business.

When developers modify the applications or functional consultant modifies any setup, changes are first promoted to the Test System where testers test the changes. Once approved changes are moved over to the Production System.

Some companies keep a separate installation as "sandbox".

Sandbox could be used for technical training. New things could be tried safely in this environment.

Some companies also keep dedicates systems for testing new releases. Such systems are called "Stage" systems. Other companies would simply test the new releases on their Test Systems.

From a technical roadmap perspective it is important to decide how many SAP installations would be there in your landscape. This has to be figured out before starting the actual installation. This decision is part of the "sizing". Each installation would have its own application tier and a database tier. Hence each installation would be using at least two machines.

Technology Stack: ABAP and Java

SAP components are either built on ABAP technology stack or on Java technology stack.

ABAP stands for Advanced Business Application Programming. It is a high level programming language created by SAP. Before sizing the SAP installation it is import to determine which technical stack would be deployed. The SAP NetWeaver platform supports both technology stacks: ABAP and Java. Either one is support as well as both are supported in conjunction. SAP components that are being implemented dictates which technology stack company will end up using.

For example Employee Self-Service component requires Java whereas ERP 6.0 component requires ABAP.

The SAP Master Guides help you find out which underlying technology stack (ABAP or Java) is behind which module.