opinion about uml design
i am pretty new in the uml design (self study). i made this scheme for a database that i have the goal of building.

I need some opinions about what is wrong, which does not make sense what can be improved or simple errors in the structure or design.

thanks in advance

![enter image description here][1]


  [1]: http://i.stack.imgur.com/q0PN3.png
opinion about uml design
===

i am pretty new in the uml design (self study). i made this scheme for a database that i have the goal of building.

I need some opinions about what is wrong, which does not make sense what can be improved or simple errors in the structure or design.

thanks in advance

![enter image description here][1]


  [1]: http://i.stack.imgur.com/q0PN3.png