Designing a domain model for a TODO list application

As I promised in my previous article this one will be about designing a domain model for a TODO list application. Then, We will implement this domain model in Hibernate, make Primefaces user interface, configure MySQL database and deploy this application on JBoss 7.1 AS. The first thing we need to do is to define requirements for our application. Then we will go through designing a database diagram and UML class diagram for application models. To create UML diagrams I am going to use ArgoUML open source modeling tool which runs on Java platform. In order to design a database diagram I am going to use data modeling functionality included in MySQL Workbench.