I'm designing a software application for my medical carrier. It is very complicated, with many parts and many small details.
Some experts advised me to divide it to parts, then design the database for each part and build it's interface. Finish one part, then move to the next part, database and interface, and so on.
When I started following their advice, I couldn't stop focusing on the database. When I finished the database of one part, I moved on to designing the database for another part and linking them together.
I neglected the interface part completely.
Should I finish my database design for the complete project, then design interface for all of it at once? Or should I stop immediately and design the interface for the finished parts first?