Seven
Principles for Enterprise Data Warehouse Design
Organizational
Consensus
From the outset of the
data warehousing effort, there should be a consensus-building process
that helps guide the planning, design and implementation process. If
your knowledge workers and managers see the DW as an unnecessary
intrusion - or worse, a threatening intrusion - into their jobs, they
won't like it and won't use it.
Make every effort to
gain acceptance for, and minimize resistance to, the DW. If you
involve the stakeholders early in the process, they're much more
likely to embrace the DW, use it and, hopefully, champion it to the
rest of the company.
Data
Integrity
The brass ring of data
warehousing - of any business intelligence (BI) project - is a single
version of the truth about organizational data. The path to this
brass ring begins with achieving data integrity in your DW.
Therefore, any design
for your DW should begin by minimizing the chances for data
replication and inconsistency. It should also promote data
integration and standardization. Any reasonable methodology you
choose to achieve data integrity should work, as long as you
implement the methodology effectively with the end result in mind.
Implementation
Efficiency
To help meet the needs
of your company as early as possible and minimize project costs, the
DW design should be straightforward and efficient to implement. This
is truly a fundamental design issue. You can design a technically
elegant DW, but if that design is difficult to understand or
implement or doesn't meet user needs, your DW project will be mired
in difficulty and cost overruns almost from the start.
Opt for simplicity in
your design plans and choose (to the most practical extent) function
over beautiful form. This choice will help you stay within budgetary
constraints, and it will go a long way toward providing user needs
that are effective.
User
Friendliness
User friendliness and
ease of use issues, though they are addressed by the technical
people, are really business issues. Why? Because, again, if the end
business users don't like the DW or if they find it difficult to use,
they won't use it, and all your work will be for naught.
To help achieve a
user-friendly design, the DW should leverage a common front-end
across the company - based on user roles and security levels, of
course. It should also be intuitive enough to have a minimal learning
curve for most users. Of course, there will be exceptions, but
your rule of thumb should be that even the least technical users will
find the interface reasonably intuitive.
Operational
Efficiency
This principle is
really a corollary to the principle of implementation efficiency.
Once implemented, the data warehouse should be easy to support
and facilitate rapid responses to business change requests. Errors
and exceptions should also be easy to remedy, and support costs
should be moderate over the life of the DW.
The reason I say that
this principle is a corollary to the implementation efficiency
principle is that operational efficiency can be achieved only with a
DW design that is easy to implement and maintain. Again, a
technically elegant solution might be beautiful, but a practical,
easy-to-maintain solution can yield better results in the long run.
Scalability
Scalability is often a
big problem with DW design. The solution is to build in scalability
from the start. Choose toolsets and platforms that support future
expansions of data volumes and types as well as changing business
requirements. It's also a good idea to look at toolsets and
platforms that support integration of, and reporting on, unstructured
content and document repositories.
Compliance
with IT Standards
Perhaps the most
important IT principle to keep in mind is to not reinvent the wheel
when you build your DW. That is, the toolsets and platforms you
choose to implement your DW should conform to and leverage existing
IT standards.