What is SAP Basis?

SAP Basis is the technical foundation of an SAP system. It is variously called NetWeaver or SAP Technology, but the scope is the same.

What Basis covers

Areas of responsibility

Area	Content
Build and operations	Installation, parameters, starting and stopping
Users and authorisations	Creating users, designing and assigning roles
Transport management	Moving developments and configuration
Job management	Scheduling and monitoring background processing
Monitoring	Availability, errors and performance
Patching	Support packages and kernel updates
Performance	Finding and removing bottlenecks
Backup and recovery	Protecting data and restoring service
Security	Segregation of duties, audit, hardening

Three tiers

Tier	Role	Components
Presentation	Display and input	SAP GUI, browser, Fiori
Application	Business logic	ABAP servers and work processes
Database	Persistence	HANA, Oracle, SQL Server

The application tier scales horizontally by adding servers, which is a large part of why SAP copes with enterprise-scale load.

Instances and work processes

The application tier is organised into instances, each with a dispatcher and a set of work processes. The dispatcher takes requests and hands them to a free work process.

Kinds of work process

Kind	Code	Role
Dialog	DIA	Interactive processing
Update	UPD	Asynchronous database updates
Update 2	UP2	Lower-priority updates such as statistics
Background	BTC	Batch jobs
Enqueue	ENQ	Lock management; one per system
Spool	SPO	Printing

Asynchronous update

Saving a document does not write to the database in the dialog process; an update process does it afterwards, so the user gets the screen back immediately.

The system landscape

Three systems

System	Code	Purpose
Development	DEV	Configuration and development; the only changeable system
Quality assurance	QAS	Testing against realistic data
Production	PRD	Live business; changes arrive only by transport

📖 Unfamiliar term? Look it up in the SAP glossary.