Questions to Consider When Developing Availability and Scalability Goals
Begin establishing goals by reviewing information that is readily available within your organization. For example, your existing service level agreements (SLAs), define the availability goals for your services and systems. You can also gather information from individuals and groups who are directly affected by your decisions, such as the users who depend on the services and the employees who make IT staffing decisions.
The following questions can help you develop a list of availability and scalability goals. These goals, and the factors that influence them, vary from organization to organization. By identifying the goals appropriate to your situation, you can clarify your priorities as you work to increase availability and reliability.
Central Purpose Questions
Answer these questions to prioritize the applications and services that are most important to your organization.
What are the central purposes of your organization?
To be successful, what goals must your organization accomplish?
Current Requirements Questions
Answer these questions to help you quantify your availability needs, which is the first step in addressing those needs.
If your organization previously evaluated the need for high availability, do you have existing documents that already outline availability goals?
Do you have current or previous SLAs, operating level agreements, or other agreements that define service levels?
Have you defined acceptable and unacceptable service levels?
Do you have data about the cost of outages or the effect of service delays or outages (for example, information about the cost of an outage at 09:00 [9:00 A.M.] versus the cost of an outage at 21:00 [9 P.M.])?
Do you have data from groups that practice incident management, problem management, availability management, or similar disciplines?
Answer these questions to help you define the needs of your users and to provide them with sufficient availability.
Who are your users? What groups or categories do they fall into? What are their expertise levels?
How important is each user group or category to your organization's central goals?
Among the tasks that users commonly perform, which are the most important to your organization's central purposes?
When users attempt to accomplish the most important tasks, what UI do they expect to see on their computers? Described another way, what data (or other resources) do users need to access, and what applications or services do they need when working with that data?
For the users and tasks most important to your organization, what defines a satisfactory level of service?
Answer these questions to clarify what services are required to meet your availability goals.
What types of network infrastructure and directory services are required for users to accomplish their tasks?
For these services, what defines the difference between satisfactory and unsatisfactory results for your organization?
Time Requirement Questions
Answer these questions to help you anticipate when availability is most important and when failures are most likely to occur.
Are services needed on a 24-hours-a-day, 7-days-a-week basis, or on some other schedule (such as 09:00 [9:00 A.M.] to 17:00 [5:00 P.M.] on weekdays)?
What are the normal variations in load over time?
During peak and non-peak hours, what increments of downtime are significant (for example, five seconds, five minutes, or one hour)?