This section lists important questions that you need to ask about your setup if you want to achieve high availability. Many of the questions are picked up in more detail in General Checklist.
1. You ask yourself how much uptime your system needs:
Ў What are the normal hours of operation (that is, the period when the system is needed):
§ During a day (for example, 12 or 24 hours)?
§ During a week (for example, 5, 6, or 7 days)?
Ў Do the hours of operation include only the time online users access the system or is the time when batch jobs or other interfaces (for example, EDI) need access counted too?
Ў What are the end users’ expectations regarding uptime during normal hours of operation, for example, can they tolerate interruptions of a couple of minutes or hours?
2. You ask yourself how much downtime your system can tolerate:
Ў What is the maximum downtime before you see a minor business effect?
Ў What is the maximum downtime before you see a severe business impact (that is, loss of business)?
Ў What is the maximum downtime before your business is at risk?
Ў Do you have special or unusual availability requirements (that is, critical periods of an application that should not be interrupted at all or where an interruption can be tolerated for less than a couple of minutes only)?
Ў What kinds of failures would cause significant problems?
3. You ask yourself about your installation:
Ў Is the SAP system installed on existing hardware or is the entire hardware new?
Ў Was the system planned with high availability in mind?
Ў Have installation options been evaluated for application servers and database server?
Ў Is special disk technology in place?
Ў Are redundant network components in place?
Ў What is the expected data volume and was database setup carefully planned?
Ў What is the expected transaction load?
Ў What are the weak points?
Ў Which components fail most frequently?
Ў Which components are the most difficult to replace in the event of failure?
4. You ask yourself about your resources:
§ Is there a budget available to implement high availability features?
§ What is the availability of qualified personnel to operate the system?
§ Is the training of qualified personnel planned?
§ Are support contracts in place?
§ Is access to your system for remote support and maintenance possible?
5. You ask yourself about the environment or other factors:
Are environmental or other failures likely, for example, unstable power supply in the area of your business?