Planned downtime is the time for scheduled maintenance and upgrade during which a system cannot be used for normal productive operations. This time is used for a variety of purposes so that a system can function optimally and reliably.
Some of the possible causes of planned downtime are as follows:
· Hardware maintenance:
· Upgrades to new releases of SAP application components, database, or operating system:
· Database reorganization:
· Database backup:
· Archiving of SAP business objects (that is, logical backup)
To archive application data, it is normally not necessary to shut the system down. You can perform Data Archiving (AS-ABAP) in online mode.
Unplanned downtime is the time during which a system cannot be used for normal productive operations due to unforeseen failure in hardware or software components, or operator mistakes.
Unplanned downtime can be extremely costly to an organization. The source of unplanned downtime can be in any of the layers that make up the complete software and hardware environment:
· Front-end and middleware services for connection to the web, including the Internet Transaction Server (ITS), the SAP Web Application Server (SAP Web AS), and the SAP Enterprise Portal.
· SAP system services of the individual application components of the mySAP Business Suite – such as the Business Warehouse (BW), Business-to-Business Procurement (BBP) – and the SAP kernel.
· Underlying hardware and software services, such as the database services, network and operating system services, and various hardware services, including servers, disks, memory, and uninterruptible power supply (UPS).