People sometimes ask if configuration management and change management
are the same functional set of tasks.
Both in principle and practice, they are two very different subject areas
but they are dependent on one another. To understand Configuration
Management (CM) better, let's review it through its four primary
objectives and benefits.
From a broad perspective, CM has four objectives as outlined in ITIL (the
IT Infrastructure Library):
First, CM needs to track all configuration items (CIs) at an appropriate
level of detail in the organization. Teams need to know this information
in order to make appropriate decisions. Thus, the CM function is tasked
with tracking new, changed, and the processing of obsolete builds -- all
of which are stored in the Configuration Management Database (CMDB) and
the Definitive Software Library (DSL).
Second, CM must be able to provide accurate information to other process
areas. There are two key aspects of this. The CM team must have accurate
information about what is in production and they must be able to
communicate it to the other process areas.
Third, data provided by CM is critical to effective and efficient
Incident, Problem, Change and Release Management.
Configuration management must be able to supply the accurate current
states to people solving incidents, problems and planning changes.
Likewise, as teams make changes to production, they must ensure that
those changes are communicated to the configuration management team so
they can update the CMDB and DSL.
If that tight connection is broken, then the configuration management
team will not be able to accurately report what is in production and both
time and money will be wasted as the other areas try to establish what is
actually in production to relative to the last known good build they are
Fourth, CM must routinely verify production configurations against stored
configurations and work to correct discrepancies. This is one of the
toughest parts of the configuration management job and where tight
integration with change management is necessary. Making sure that the
current production builds match the last known good build is both the
Achilles' heel of the process chain and where a detective control can
make a world of difference.
By detecting changes to production builds and accurately reporting
variances between the last known good state and the current state, the CM
team can work with other teams to determine what corrective action is
These objectives are important because of what they enable for the
organization. The following benefits can be accrued by having effective
Build Variance Detection -- By knowing the last known good
build for each CI, changes can be detected. These detected changes can
then be investigated to see if there is a process problem, human error or
a security incident that requires immediate attention. Detective controls
are vital to change management and this means configuration management
must be able to supply CI build information a timely and accurate manner,
Efficient Change Management -- If a person doesn't know what
the current state of the CI is and what he/she is starting with, how can
that person arrive at the desired end state? In other words, unless
engineers know for sure the configuration of a given CI, they may plan a
change incorrectly, resulting in availability problems, missed dates and
poor performance. If the CIs are inaccurate, an inordinate amount of time
is spent simply taking inventory the CI and figuring out how it is
configured versus being able to take the configuration for granted and
beginning with the engineering of the change.
Data Mining for Problem Management -- Engineers investigating
incidents can mine configuration records to look for corresponding
incidents when certain CIs are used in a certain way.
For example, they may investigate all Windows XP SP2 builds and find that
release 3.0 of a vendor's software causes stability problems, whereas
version 2.9 did not. If the configuration records are in error, they may
miss causal relationships that would allow them to identify underlying
problems and thus miss the opportunity to develop solutions.
Enhance Ability to Rebuild -- If a CI fails, is stolen or is
involved in a disaster, it is far easier to rebuild it if the final
production build of the CI is known. Moreover, if the final build exists
as a drive image, an engineer or technician can simply make sure the new
hardware matches the last known good build and then restore the image.
Recovery processes that used to take hours manually can be done in
Assist with Budgeting -- Understanding what hardware and
software goes into a given CI allows for proper costing to serve as an
input in the budget planning process. Costing information isn't just
important for planning purchases, but also for ensuring the firm has
adequate insurance. Tracking CIs also allows IT to rapidly report what
capital assets are in use, what are being decommissioned, or transferred
to other departments or divisons.
Assist with Licensing -- Understanding what software is
deployed allows management to track quantities of the various tools in
production and validate that license counts are properly managed. Firms
do not want to have too few licenses and risk a legal dispute, and they
do not want to have too many and have excessive expenditures.
Configuration management offers many positive benefits to organizations.
The challenge for the team is to keep timely and accurate records that
are accessible to the functional areas that need them. This requires not
only sound processes, people and technology, but also the unwavering
support of management.