Databases Reference
In-Depth Information
CHAPTER
6
Providing Business
Requirements
Now that the project is set up, it is time to get started on the work. The next
step of the project is to collect requirements. The intent is the same as
with any other system design project: to ensure that the ultimate system
serves the intended purpose. However, the requirements needed to design
a data warehouse are distinctly different from those for operational systems.
Operational system requirements are very specific to ensure that the business
function or transaction is completed accurately. For example, a concrete set of
criteria must be met to complete an online product purchase. Data warehouse
requirements are often general and much more fluid. In a company, there may
be a need to produce a report of the top twenty-five corporate customers and
their year-to-date purchases, but tomorrow the hot topic needing attention
may be identifying bottlenecks in the distribution channel. These differences
create challenges for projects that use the same approach for a data warehouse
project as for an operational system project.
This can lead to a communication gap between business and technical
staff members when trying to gather requirements for a data warehouse. The
systems community feels like the business does not know what they want
because when asked, ''What report do you want first?'' they get a different
answer each time. Likewise, there is frustration on the part of the business
because requests are made, but IT does not deliver what is really needed.
The systems people really want to deliver something useful. The business
people really do know what they are doing, but numerous fluctuating factors
create new reporting and analytical needs. The challenge for a data warehouse
projectistobothsupportthebusinesstodayandbeabletoadapttomeet
future demands too.
This chapter explains what requirements are needed for the DW project and
how to effectively gather them. It will help anyone who participates in the
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