To keep your sanity, it's best to start with a general area of interest. Once you've reviewed the literature on your general area of interest, it'll be easier to create a problem statement from what you've found. Basing your business problem off of the literature is going to save you a lot time and energy further down the road.
Students run into two major problems when they choose a business problem without looking at the literature first.
If you work for a company that has high employee turnover and you'd like to find more information about how to retain employees, these are the steps you could take.
While reviewing the literature, look for the statistics or data that interest you. It's easier to use something you've already found than to search for something that may not exist.
Trying to locate data or statistics based on what you'd like see instead of what's available can be tricky. Your preconceived ideas for data or statistics may or may not exist. If they do exist, they may not exist in the way you expect.
The easiest way to locate a gap in the literature is to review the literature related to a topic you're interested in. While reviewing the literature, do you notice any themes, industries, or groups that aren't being addressed? Below are instructions for locating a gap in the literature.
Most dissertations will have a section discussing opportunities for further research. Those students have already done the leg work and have insight into the literature. If their idea for further study intrigues you, go out and research to confirm that there is still a gap in research.
Video: Walden DBA Problem Statement Tutorial (YouTube)
Recorded September 2013 (15 min 20 sec)