"Object-Oriented Programming" computer engineering project: an architecture firm software

As part of a university course called "Object-Oriented Programming"at UNED, I developed this project. It is an exercise on class diagrams and hierarchy. I used bluej, as specified in the course description.

The main menu allows the user to choose between 4 types of users: each one can access a different set of subprograms.

The subprograms revolves around adding new data to the list of users or the list of projects, changing or deleting it, and showing selected data.