This forum is for users of Oracle Designer, a CASE tool that can do everything from logical modeling to code generation. Wonderful tool, but Oracle is no longer actively maintaining it.
I have the feeling that you are not trying to design your Ticket Management system with Oracle Designer. Which means that you are asking in the wrong forum. If you're wanting to write an Oracle Form, there is a separate forum for that. No matter what, you will need to give a good deal more information about what you're trying to do. And don't expect forum participants to do your design work for you - these forums are better at giving you a little help when you are stuck with a specific problem.