Need of UML Diagram

Question

Please help me know as to when it(uml) is necessary. I was told that generally UML are drawn for web based application developement, for desktop based, DFDs and ERDs are used. My university requires all the diagram(uml,dfd,er). please let me know if my information is correct? Thank you

Answer 1

UML Diagram are imporant because it help the person to understand the relationship and dependency between different class present in the code(Class Diagram).

Flow of the program(Sequence Diagram , Activity Diagram). Help to improve the program architecture etc.

And read about different type of UML diagram you will get more information.

Answer 2

Your needs in using UML depends on your position and your (self)education.

• Some companies use UML. So, you would need it to get a job in them. Just now your university requires UML diagrams, so there IS a need in them, isn't it?
• If you know UML a bit, you could understand the thoughts of your colleague who wants to share them with you this way.
• If you understand the language of a UML diagram, you can use it for improvement of your thinking on the problem. So, you can think into the problem deeper and faster than without a tool. You should be really well acquainted with the tool though, for when inventing something new, you need to think on the domain problem, not on the language problems. But you don't need to know all the rules for this level of use yet.
• If you know UML so that you can draw diagrams up to their strict rules, you have two more uses of it.
  • Translating your knowledge of the problem from one level of abstraction to another and modelling these levels up to the strict rules, you are filtering many misunderstandings in the already accepted model and can practically debug the model before coding. It can save much time and money.
  • While you are making the diagrams according to strict rules, you can collaborate on the model with your colleagues. It is always better if you can express your ideas more precisely.

As for technology limitations, you can use UML very widely, even out of the IT needs. As for IT, only GUI creation is supported badly. And anonymous classes are almost not supported in class diagrams at all (in behaviour diagrams they work OK).

Answer 3

DFD (datya flow diagram) and ERD (entity relationship diagram) diagram are tools for structural analysis and design, this is way to build structural application (data bases and functions). UML support quite different paradigm: object paradigm - we build application as collaborating objects. DFD and ER (ERD) diagram is not part of UML. We can use ER diagram for data base modeling and join to UML domain model by the ORM (object-relational mapping, implemented e.g. by Hibernate).