UML 2 Sequence Diagrams

Welcome to my tutorial on UML 2.0 Sequence Diagrams! Sequence diagrams model interactions in your program and provide you with a logical way to layout your system. They are about showing the order of interactions between the parts of your program.

In making sequence diagrams, you describe which interactions are triggered and when. They focus in on the order of events in all interactions.

The video covers just about everything and the cheat sheet above is there to re-enforce the specifics.

[shiftrunstop]

I was starting to panic, Last semester I had linear algebra, you saved me. This semester I have a software engineering module with use cases and sequence diagrams, you saved me. You have the most useful channel on youtube, Thank you for helping me get furter into my degree.

[임창수-cc]

Sequence diagram is one of the best tools to understand how the system works. Really nice tutorial. Thank you.

[the_wizard_exe]

what a masterpiece you were the only one who explained that very clear, full, aproaching every item than others, thanks

[isramos]

You're a walking encyclopedia, man! 
You're videos are a great way to get us introduced to new topics or brush up on long seen stuff. Great job!

[RajaseelanGaneswaran]

If there's one thing you do well, it's summarizing these concepts in a beginner friendly way. Love your channel.

[derekbanas]

Oh no, another fight is brewing in my comments.

It is so nice to be the only guy on YouTube that doesn't sell anything. If anyone ever catches me trying to sell something feel free to hunt me down. I'm sure you guys are smart enough to find me :)

[amodh]

too complicated for me to understand! You could've started with an easy example and then shown this example which has everything crammed into it.

[angelakeller]

If this tutorial is too complicated for you, then start watch the Object Oriented Design Tutorial. There Derek explains the sequence diagram by building it step-by-step. Just as a hint. =)
Of course, without any knowledge of sequence diagrams, you can hardly understand this video.
But thanks again Derek, for making my exam preparations much easier and more interesting.
Greetings from Switzerland!

[mohammadpatel]

Quality videos, really helps when your lecturer is useless

[dominikachaciej]

Thank you, I think this is the most complete tutorial on Sequence Diagram, I could find here.

[kevinbs]

Thanks, this is helping me put together the lectures and examples for those people who are taking the exams later on. :)

[risteva]

Derek Thanks for this tutorial.I like it.Please do not be discourage about any bad comments please keep going.It is not easy to teach but i think you are doing great.

[Truthiness]

Ah, good to have confirmation from someone who knows so very much about this business. Keep up the amazing video series and I'll not only continue to lead everyone else to your superior tutorials, but I'll also keep posting with this and other wacky avatars ^.^

[MoinKhan-lutb]

-best sequence diagram video on youtube .... u coverd all the aspects as well, the sequence fragments too .. !!!
- thanks : keep the good work up

[derekbanas]

Thank you :) This and my OOD tutorial were my favorite tutorials to make. I'm glad you liked it

[OverG]

A little advice for viewers: If you want to make these "fancy" diagrams like Derek, look at Obeo UML Designer plugin for Eclipse. BTW, Great video!

[derekbanas]

Nếu tất cả chúng ta sẽ lắng nghe những người khôn ngoan của cuộc sống trong quá khứ sẽ là tốt hơn cho tất cả chúng ta.Một giáo viên chỉ là tốt như các sinh viên của mình

[patrasculucian]

Things I understood from this video:

- sending a signal message through a filled arrow will wait for a response
- sending a signal message through a normal arrow will not wait
- this messages can be also nested

Sequence fragments:
- are boxes that surround interactions
- they got fragment operators in the top-left corner

- optional - will run only if it fulfills a condition
- negative - will not be used
- reference - will reference to a sequence diagram and call it
- a reference sequence diagram is like a method that we can call whenever we want. But instead of "method" it is called "reference".

- loop is just a loop that will run as long as a condition is fulfilled
- loop (5) - will loop 5 times
- loop (x, y) - will loop from x to y

- par (parallel) - the interactions from it can run in the same time
- alt (alternative) - if - else statements where "if" is called "alt"

- assert - if the interactions from this fragment will not fulfill the conditions we will throw an error. Similar to Java's try-catch blocks, or throws.

- break - will break from a loop if a certain condition is fulfilled

- critical - I didn't quite get this.
- I think it is like a reverse loop (don't do this until that happens)

Time Constraints:
- the arrows are diagonal
- we will specify a waiting time for signals while calling or replying
- sending signal line will be a normal line
- respond signal line will be a dash line

Lost Message: *black hole*
Found Message: *black hole*

I found this lesson very hard for a beginner like me.
But writing these down totally helped with the grasping process.

[BaralGanesh]

Thank you for excellent lessons, I have exam next tomorrow there were some confusion but luckily I found this and two previous videos. Pure and simple. Many thanks for your effort.

[ZastinHuynh]

Your videos are great and awesome, To be honest I get much more out of your video than the lectures at my university. I won't name it but it's top 10 here in Australia. I would make my way to class if my lecturer sounds like you xD