Databases Reference
In-Depth Information
and often have a realistic understanding of the difficulties in weaving their
way around the data in its current form.
RECOMMENDATION
Even if the most experienced staff members cannot
participate full-time on a data warehouse project, these valuable resources need
to provide regular guidance and direction. From a business perspective, get other
staff members to pick up some of the daily responsibilities for key personnel. This
may mean brining in additional help— you can't expect everyone else in the group
to go from 110% to 120% effort. From a technical perspective, it is important to
keep your staff involved and informed about what the data warehouse is, and how
and why it is built. It is risky to turn the entire project over to a third party because
they will eventually leave with all the business and technical knowledge.
At a minimum, hire contractors to backfill some of the daily operations work so
that key technical personnel (DBAs, architects, and lead developers) are able to
participate in the project. Another technical resource constraint is access to the
key individuals who understand and intimately know the source system and data.
The data warehouse team must have regular access to these individuals in order to
understand the existing data. Major errors can be made in pulling data without the
appropriate background knowledge. This is often not discovered until much closer
to deployment.
Finally, if the appropriate resources are not being made available from
a business and/or technical perspective, then the true priority of the data
warehouse must be evaluated.
Finding Lost Institutional Knowledge
Over the years, application systems have been developed to automate business
processes and apply business rules and logic. In addition to these systems that
run the business, a series of programs, SAS routines, or complex spreadsheets
have been developed to meet reporting and analytical needs. Many of these
reports and analyses have now been in place for years, but over time the
fundamental purpose of a report may be lost.
In addition, the business rules underlying the criteria for the report have
been embedded in code that is simply run on a regular basis. Too often, a
description of these rules and the business rationale behind them has been lost.
Therefore, when the data warehouse team is applying pressure to understand
the current business practices, the business community may honestly no longer
have that knowledge. This is a fairly common situation, and one that does not
warrant looking for someone to blame. It is important to acknowledge that
this is the case and work from there.
RECOMMENDATION
One's first impulse is to read the programs or dissect
the spreadsheets. After many hours of tedious work, the business logic can be
