Availability Guide for Change Management

Availability Guide for Change Management–125506
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Change Control
Overview
Making changes to your system and application environment can increase the
effectiveness of your operations—or can result in confusion and problems. The
difference between success and failure depends on how well your organization manages
change. By establishing a formal change-control process, you can ensure that change
proceeds smoothly and with minimal impact on system and application availability.
This section provides information to help you ensure that changes are implemented
successfully. Topics described in this section include:
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How Tandem defines change control
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How change control affects system and application availability
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The requirements for successfully implementing a change-control process
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The phases of the change-control process
What Is Change Control?
Change control is the process for proposing, planning, implementing, and testing
change and is a key requirement for minimizing the duration of planned outages (system
or application downtime that is planned or scheduled). Change control ensures the
successful migration of a system or application from one stable configuration to another
by:
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Ensuring that the scope and ramifications of the change are fully understood.
Thoroughly assessing the impact of change, determining what resources will be
required to implement the change, and creating a plan for the change can help
minimize planned outage time.
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Providing a recovery plan.
A recovery plan with written instructions should be developed in case the change
does not work. Providing a recovery plan reduces planned outage time by ensuring
that system operation can be quickly resumed if the change cannot be implemented
successfully.
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Ensuring that problems and errors are anticipated and reacted to appropriately.
A change plan should include a detailed sequence of events including “go/no go”
criteria and contingency plans at each step in case problems or errors occur.
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Maintaining the security of your system and applications.
Controlling change is an important part of maintaining the security of your system
and applications. If you do not control who makes changes and when, you may put
your system’s security at risk. If there are no controls, frequent changes and
changes by unauthorized personnel may damage the stability of your system.