As you can see in the model, there are eight classes, each with a certain number of attributes. There are also several relationships: one (User_UserGrp) is a many-to-many, the others are one-to-many's.
The main class is "Ticket", both in a "semantic" sense and in terms of number of attributes/relationships. The ticket has a priority ('hign', 'normal' or 'low'), a resolution ('resolved', 'not to be solved', 'duplicate', etc.), a type ('problem', 'new feature', 'improvement', 'maintenance'), and is associated to a project.
Also, it is interesting to see that it has tree different relationships with "User" to specify who reported the ticket, who is assigned to it, and who is  the approver.
Another interesting class is "Project". A project is a containter of tickets (as we've already seen) and of versions. Also, a project has a user in the role of leader.
Finally, User, UserGrp and User_UserGrp are the basic user model common to all Portofino applications, which can be set up easily using the "create user management" functionality upstairs.

A detailed view of the classes follows.

Ticket

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
code	TEXT		the ticket code
project	RELATIONSHIP	project	the associated project
type	RELATIONSHIP	ticket type	the ticket type
description	TEXT		a brief description of the issue
priority	RELATIONSHIP	priority	the priority (low, medium, high)
resolution	RELATIONSHIP	resolution	the resolution
state	WORKFLOW		one of the worflow states
creation date	DATE		the creation date
update date	DATE		the last update date
summary	TEXT		A brief summary
assigned to	RELATIONSHIP	User	The user that has to fix it
reported by	RELATIONSHIP	User	The user who inserted the issue
expiry date	DATE		the expiry date
approver	RELATIONSHIP	User	The user that has to declare the resolution
close date	DATE		The date when the issue is closed

Priority

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
name	TEXT		e.g. 'high', 'normal', 'low'

Project

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
name	TEXT		the project's name
url	TEXT		the website url
description	TEXT		a brief description
code	TEXT		a short code
leader	RELATIONSHIP	User	the project leader

Version

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
name	TEXT		The version name
description	TEXT		a brief description
planned date	DATE		the planned date
actual date	DATE		the actual date
project	RELATIONSHIP	project	the related project

Ticket type

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
name	TEXT		'Improvement', 'maintenance', 'new feature', 'problem'
description	TEXT		a brief description

Resolution

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
name	TEXT		a short name
description	TEXT		a brief description

User

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
login	TEXT		user's login
password	TEXT		user's password
email	TEXT		user's email

UserGrp

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
name	TEXT		The group name (e.g. 'Users', 'User admins')

User_UserGrp (as a relationship)

ATTRIBUTE	TYPE	RELATED TABLE	NOTE
user	RELATIONSHIP	User	user reference
user group	RELATIONSHIP	UserGrp	group reference