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Unit 12: Metadata and Warehouse Quality

derived from data of the lower layer. Data sources, also called stored in open databases, form notes
the lowest layer. They may consist of structured data stored in open database system and legacy
systems, or unstructured or semi-structured data stored in files.

12.1 Metadata and Warehouse Quality

To be successful throughout the process, it’s important to know what you did right and wrong. In
essence, you need “meta data” about what you’re doing to accurately measure quality. Successful
measurement is the key to warehouse quality, but how do you measure a data warehouse? Wells
and Thomann offer a number of different methods, dimensions, and levels for understanding
data warehouse measurement. To begin, Thomann describes three “types” of success and their
definitions as they relate to data warehousing:
1. Economic success: The data warehouse has a positive impact on the bottom line.
2. Political success: People like what you’ve done. If the data warehouse isn’t used, it’s
obvious that you failed politically.
3. Technical success: This is the easiest to accomplish. However, don’t overwhelm your users
with too much technology. Success also means that the chosen technologies are appropriate
for the task and are applied correctly.
Since there are three ways to succeed, Wells responds, there are three ways to fail. Quality, he says,
can be defined as the degree of excellence of something. “But this is a very subjective measure,
and you can make it more subjective through measurement.” Three main areas are detailed in the
paragraphs below, which can be used to assess the overall quality of a data warehouse.

12.1.1 Business Quality

Directly related to economic success, business quality is the ability of the data warehouse to
provide information to those who need it, in order to have a positive impact on the business.
Business quality is made up of business drivers, or concepts that point out a company’s strategic
plans. So organizations should be concerned with how well the data warehouse helps accomplish
these drivers, such as changing economic factors, environmental concerns, and government
regulation.

Does the data warehouse align with business strategy, and how well does it support the process
of strengthening core competencies and improving competitive position? What about the
enablement of business tactics? Does the data warehouse play a tactical role, so that it makes a
positive day-to-day difference?

12.1.2 information Quality

Information doesn’t have value if it’s not used. Therefore to have information quality, the focus
should be on the integration of information into the fabric of business processes, not on data
quality itself.
Information quality is the key to political success, which was described above as people actually
using the data warehouse. “Some companies don’t tell users it’s there,” Thomann says, “so they
may not understand the warehouse or know how to use it.” Success in this area means providing
awareness, access tools, and the knowledge and skills to use what they’re given. For example,
could your users easily make the shift from using greenbar reports to a multidimensional data
model? Then, assuming they understand the warehouse, can they get to the data easily? Who
gets the data? How frequently? How and when is the data used? You may be able to provide 24x7
access, but what if users are at home?

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