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8.2.2 Points of control
pool of available numbers on the PBX for the employee’s work location (or
some other applicable criteria).
► Organizational e-mail address: The RFC-822 (SMTP) address generated
by the IT staff for the user. The address must be unique against all other
SMTP addresses currently in the system used for e-mail. It might be
generated algorithmically using elements of the user’s full name, department,
or some other data.
In this example, note that we have three authoritative sources for the four
attributes. HR is the authoritative source for the name and employee number,
facility telecommunications is the authoritative source for the phone number, and
IT is the authoritative source for the e-mail address. For purposes of this
example, we do not need to precisely define what the “name” attribute consists of
(we discuss issues related to names in the section on “Multiple identities” on
page 322).
Multiple authoritative sources for data is extremely common, and the number of
authorities seems to increase in direct relationship to the size of the organization.
This is simply an observation based on our experiences, but anyone who has
worked for a large multi-national organization would probably agree. Larger
organizations require larger numbers of specialized administrative staff groups,
which in turn are dedicated to specific areas or spans of control. A human
resource specialist is highly unlikely to also have the expertise and responsibility
for managing the company’s telephone PBX system. And note that the
specialization of data administration may not be limited to internal staff groups.
Some organizational systems may be outsourced and controlled by third parties.
For example, the buildings and parking structure access might be controlled by
an outside organization.
We are not implying that any two organizations of similar size have the same
number of data authorities. We are just making the point that single, centralized
authority for all person data within an organization is highly unlikely because
directories have traditionally been deployed for widely different business
functions. And we are not saying that single, centralized authority is “better” than
multiple authorities. The real concern when there are multiple data authorities
are the points of control and how the data is managed, which we discuss in the
next section.
A point of control is defined as an interface that provides the ability to perform
write-operations on all or a portion of the person data record. A write-operation
can consist of and add of a new record, modify of an existing record, or delete of
an entire existing record. A read-operation is a retrieval only of data without
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