Whence Data Quality?

Database Testing

In the September survey, 66 percent reported that they do some form of database testing. In the July survey, I asked about database regression testing, a more complicated form of database testing, and found that less than half of respondents do that form of testing. Figure 5 depicts the relationship between various forms of testing and overall database quality. Many respondents indicated that they take more than one approach to database testing, so the results are commingled. The organizations that do no database testing at all seem to be in the worst shape, which should come as no surprise. Testing at the end of the lifecycle is an improvement, but appears to be the least effective time to test—apparently we need to rethink traditional approaches. Testing at the end of each development iteration is more effective still, but taking a test-driven design (TDD) approach appears to be the best approach.

Figure 5: Database testing and data quality.

Data Modeling

The survey also asked about the approach to data modeling by project teams, and Figure 6 correlates the answers to data quality. It's interesting to note that evolutionary/agile approaches to data modeling prove to be just as effective as traditional/serial approaches, and that both approaches are better than not data modeling at all. What we don't know from the survey is how much data modeling is actually occurring. In my experience, traditional teams seem to do a lot more modeling than agile teams, so potentially, agile teams are achieving the same results as traditional teams for a smaller investment. I suspect that a more detailed study is required to tease out what is really happening.

Figure 6: Approach to data modeling and data quality.

Conclusion

These surveys have shown that we clearly have some serious problems when it comes to data quality. At www.ambysoft.com/ surveys, I have posted the source data (with the e-mails removed), the original questions, and PowerPoint slide decks summarizing critical findings from all of my surveys, including the most recent one. Please use these assets to communicate the challenges with traditional approaches to data management within your organization. Better yet, please analyze the data for yourself and report your findings back to the IT community. Now is the time to start digging ourselves out of the "data morass" that we find ourselves in.