Chapter 3: Change and Configuration Management 39
Change can be broadly categorized into four groups, each requiring its own style of
management. The groups are:
◆Major change. Significantly impacts the IT environment, and requires major resources
to plan, build, and implement (for example, upgrading all Exchange 2000 Server
hardware).
◆Significant change. Requires substantial resources to plan, build and implement (for
example, upgrading to a new Service Pack).
◆Minor change. Requires no significant resources and doesn’t significantly impact the IT
environment (for example, modifying certain Exchange system policy settings).
◆Standard change. Follows a standard documented procedure, which should not affect
the IT environment at all (for example creating new mailboxes).
Of course, the more changes that you can successfully fit into the latter two categories, the
less likely there will be a significant disruptive impact upon your organization. This does
not mean that you should avoid significant or major change. Indeed, major or significant
change can often prevent problems with availability management later on. For example,
deploying a new Service Pack throughout your organization may enable you to avoid
encountering problems with your environment.
By thoroughly documenting as much of the Exchange environment as possible, including
how changes should be made, you can maximize the number of changes that are catego-
rized as minor or standard, thereby significantly decreasing the costs associated with
change.
Change management involves the following five activities:
◆A change is requested.
◆The impacts (technical and business) of making the change are assessed (this includes
testing in a lab environment).
◆The change is authorized.
◆The change is handed to Release Management for implementation.
◆The change is verified.
Numerous parties should be involved in Exchange change management. To see how these
parties would typically interact, examine the following major change, upgrading all servers
running Exchange to new hardware.
Step 1 – Request for Change Is Submitted to Change Manager
Everybody in your organization should be authorized to submit a request for change
(RFC). In this scenario, the likelihood is that the RFC has come from a member of your IT
staff.
Other change sources include IT staff responsible for problem management (for example,
root cause analysis), service level managers who are planning to sell new kinds of service
or upgraded levels of existing service, and so on.