The fledgling system must do some things right, or it would not have been launched, and it might do other things as well as the designers could conceive. Still other features might work as built but not as intended, or they might be more difficult than they should be. In essence, there are gaps and protrusions between the shape of the system and the solution space it is meant to occupy.
A new system does not automatically become better fitting through use. Most of the time, the system trains its users—painfully. The system can be changed to fit its solution space better—even as the solution space continues to change over time—thereby filling the gaps and filing the bumps, but only by deliberate action.