High-Availability Introduction

Keeping the SAP system available refers to the fraction of time the SAP application can be used for its intended purpose: performing business transactions. When the system is not available, this is considered downtime. Many factors impact a system's availability, against which preventative measures can be taken.

There are several levels of components or functions that make up a complete mySAP.com environment, as listed in Table 5-1. From a user's point of view, the application is the availability of a service level. From an IT perspective, the availability is the sum of all the functions provided in the different levels of the entire SAP application environment.