A ForkNode is *not* represented as a diamond as specified around 3:20. It is represented as a line-segment, it can be either a horizontal or vertical, as specified in the UML 2.5 SuperStructure specification in Figure 15.29. From UML SuperStructure 2.5 section 15.3.4: " The notation for both ForkNodes and JoinNodes is simply a line segment, as illustrated on the left side of Figure 15.29 (not necessarily in that orientation).When used, however, a ForkNode must have a single incoming ActivityEdge and usually has two or more outgoing ActivityEdges, while a JoinNode usually has two or more incoming ActivityEdges and must have a single outgoing ActivityEdge."
I can't imagine finishing a big project without sequence diagrams. It does seem like more organizations I have dealt with lately are trying to work with just simple usage descriptions. I just go and make my sequence diagrams on my own. Magically I continue to finish my projects while others have been failing at an increasing rate. I get the Ed Helms thing all the time :)
Thank you :) This is technically a Java tutorial as it is a tutorial for all languages. I had to teach UML so I could dive into the complexity that is OO analysis. Then I'll dive in head first for refactoring. After that everything is easy
Thank you :) I do my best to fill in the gaps. It is amazing to me that colleges don't teach this topic. When I first started working for Apple it was a must that I understood Object Oriented Design and how to use UML diagrams.
Thank you very much :) So far the voting is going the Game / Android route but that could change. I may be able to slip in Hibernate or Spring? What are you looking for? Either way I'll cover J2EE after the other tutorial. This is just a vote on which is covered next. It isn't an either or vote
What I'm showing here are the standardized rules for many UML diagrams. In the real world you will sometimes leave out explanations in the simple part of your system, while you'll explain beyond the standard when needed. As this series continues I demonstrate that because I create very detailed sequence diagrams
Hello, I use UMLet. It works on every OS and can either be used as an Eclipse plugin, or on its own. Visual Paradigm is the best in my opinion, but it is also expensive. Most of the time for tutorials and in the real world I use a paper and pencil, or a white board.
Derek, I keep shying away from using UML notation, since I keep ending up with hybrid diagrams. Your videos have really helped to clear things up. Many thanks and greatly appreciated.
Eventually you'll find a few diagram tools that work best for you and then use them. I normally write a use case description and then a sequence diagram and that is it. Check out part 1 of my object oriented design tutorial to see what I use in the real world
I normally design all of my logic in a sequence diagram after I complete the usage case. The class diagram is just used to provide an overview of the system. I hope that helps
I'm looking at these videos for possible use by developers in my company and I noticed something at about 2:40 that I'm not sure is right. Here a diamond is being used to execute activities in parallel however my understanding of the semantics of activity diagrams is that a diamond only produces one "activation token" and so only one of those activities can be executed. Normally there would be guard conditions coming out of the diamond to determine which path is picked. The correct notation for what you are describing would be a solid line which generates multiple activation tokens on exit. The merge should also be a solid line as execution continues when all inputs have triggered. The way you have it execution will continue after only one activity completes.
Silvana Donato See the official specification of UML 2.0 (10 years old and I suppose Derek used 2.0 as a shortcut for 2.x), 12.3.30 on fork nodes (the fat black bars). Those are for concurrent flows. Derek is wrong.
Peter Kelley Yeah, this is all a bit confusing. But looking at the specs it seems that the fat bars are called forks for outgoing lines and joins for incoming. Accordingly, the diamonds are called decisions for outgoing and merges for incoming. So, technically what you called a "merge" should be a "join". Just to avoid confusion. =)
Peter Kelley Yeah, this is all a bit confusing. But looking at the specs it seems that the fat bars are called forks for outgoing lines and joins for incoming. Accordingly, the diamonds are called decisions for outgoing and merges for incoming. So, technically what you called a "merge" should be a "join". Just to avoid confusion. =)
Hey Derek Banas, Nice video couple of stuff I would like to point out. The merge and fork you are showing is actually junction nodes (however your depiction is correct). Merge and fork actually is a rectangular black thick line, the arrows differentiate which is fork and merge. I use umlet a lot hence I know the differences.
2:33 The words "All at the same time" sound confusing here - does it mean that all actions must be performed at the same moment of time or is it just used as kind of "AND" logical operator which waits until all the actions get done and only after that it goes on?
I think the ones who disliked this video are the ones who make videos themselves but got jealous of Derek's videos haha. I just started learning UML Diagrams yesterday and I already learned so much in only two videos.
awesome. 2 follow up Q's: 1. As an engineer, is is crazy to expect business people to provide activity diagrams? (As opposed to "umm.... just make it work by next month") 2. Why do you sound EXACTLY like Ed Helms?
I agree this is well put together. Seems like those big tech bibles are mostly self promotion books from what I can see. You have to do a lot of reading before you get into anything useful.
This tutorials were what I was always looking for !! Thanks a lot Derek, Coding is not much a big problem for me but I always struggled when I was asked to develop something from scratch, a lot of back and forth development cycles messes the whole project. Now I know how to proceed for new projects from scratch !
I'm very happy that I could help with this. Yes there is a big difference between writing simple programs and large professional ones. I couldn't imagine how I'd make a large application without UML.
@Peter and Silvana, indeed, I'd use a fork/join for that. But as far as I remember activities after a fork would not be executed necessarily at the same time (as the author states in his example) as the only condition to 'join' after the 'fork' is that all the activities are completed, whenever it is.
Also at about 4:50 the object node has 2 outgoing flows. I believe that there is a default in this circumstance but I always forget whether it is a fork or a merge. Better to show what happens explicitly.
Thanks for all these awesome tutorials :) Instead of having to read a bunch of ppt slides for an exam, I just listened to those tutorials and took some notes and I was done with my diagrams :) Subscribed to your channel. You seem to have many interesting tutorials!
Don't worry. I hear about how outraged students are over the current system all of the time. I have the feeling that you'll see great changes in the education systems over the next few years. It is just to bad that current students will have to pay the price for that to happen. I've never been money motivated so I don't understand why so many people stand in the way of progress for a few extra bucks?
What would be the best UML diagram to use when creating an app with a similar UI to Instagram? Followers. Small text posting. Not much customization like Facebook. Sweet and simple for now.
Not to be a putz but at 1:26 you called the fork a merge. No big deal, the kind of mistake that we all make. Overall a very awesome tutorial, thank you for making them. :D
Very helpful, clear, simple and objective explanation (as always).Derek, thank you for help me revise, improve and learn so many important concepts in diverse subjects.
Are you sure about what you said over that Vertical Fork / Join (what you called partition - 7:54)? Wouldn't it be used when 2 different operations would work at the same time? (sorry about my english...)
well explained. just I think you forgot to mention that the partition also can be used in the case of multiple actions happening for example if passenger verified at the check-in counter, the boarding ticket will be provided and at the same time luggages will be collected.
I will never understand why universities don't spend more time on courses that directly relate to the degree instead of unrelated courses?
Me lo chiedo anche io fratè
I don't understand either. And I am here to learn. Lmao
Me three!
Funny you say this, I am watching this video for a course in my MS in ML Engineering.
A ForkNode is *not* represented as a diamond as specified around 3:20. It is represented as a line-segment, it can be either a horizontal or vertical, as specified in the UML 2.5 SuperStructure specification in Figure 15.29. From UML SuperStructure 2.5 section 15.3.4:
" The notation for both ForkNodes and JoinNodes is simply a line segment, as illustrated on the left side of Figure 15.29 (not necessarily in that orientation).When used, however, a ForkNode must have a single incoming ActivityEdge and usually has two or more outgoing ActivityEdges, while a JoinNode usually has two or more incoming ActivityEdges and must have a single outgoing ActivityEdge."
What I've learned is that NO MATTER WHAT the freaking UML diagram is wrong. According to my fucking SE professor.
I can't imagine finishing a big project without sequence diagrams. It does seem like more organizations I have dealt with lately are trying to work with just simple usage descriptions. I just go and make my sequence diagrams on my own. Magically I continue to finish my projects while others have been failing at an increasing rate. I get the Ed Helms thing all the time :)
I'm glad you enjoy them. I don't think about negative comments. Actually some of them help me improve my videos :)
Thank you :) This is technically a Java tutorial as it is a tutorial for all languages. I had to teach UML so I could dive into the complexity that is OO analysis. Then I'll dive in head first for refactoring. After that everything is easy
Thank you :) I do my best to fill in the gaps. It is amazing to me that colleges don't teach this topic. When I first started working for Apple it was a must that I understood Object Oriented Design and how to use UML diagrams.
Hello May I know where is the part1?
Thank you very much :) So far the voting is going the Game / Android route but that could change. I may be able to slip in Hibernate or Spring? What are you looking for? Either way I'll cover J2EE after the other tutorial. This is just a vote on which is covered next. It isn't an either or vote
You're very welcome :) I'm glad I could help
What I'm showing here are the standardized rules for many UML diagrams. In the real world you will sometimes leave out explanations in the simple part of your system, while you'll explain beyond the standard when needed. As this series continues I demonstrate that because I create very detailed sequence diagrams
Thank you :) I do my best to make learning easy. I'm glad you liked the videos
Hello, I use UMLet. It works on every OS and can either be used as an Eclipse plugin, or on its own. Visual Paradigm is the best in my opinion, but it is also expensive. Most of the time for tutorials and in the real world I use a paper and pencil, or a white board.
Derek, I keep shying away from using UML notation, since I keep ending up with hybrid diagrams. Your videos have really helped to clear things up. Many thanks and greatly appreciated.
I'm very happy that I was able to help :) You're very welcome
Honestly, what would I do without you?!?
Nicole Braybrook Thank you :) I'm glad to be able to help
check other tutorials
You're very welcome :)
Eventually you'll find a few diagram tools that work best for you and then use them. I normally write a use case description and then a sequence diagram and that is it. Check out part 1 of my object oriented design tutorial to see what I use in the real world
I normally design all of my logic in a sequence diagram after I complete the usage case. The class diagram is just used to provide an overview of the system. I hope that helps
Cheatsheet needed....u r tutorial is awesome
I'm looking at these videos for possible use by developers in my company and I noticed something at about 2:40 that I'm not sure is right. Here a diamond is being used to execute activities in parallel however my understanding of the semantics of activity diagrams is that a diamond only produces one "activation token" and so only one of those activities can be executed. Normally there would be guard conditions coming out of the diamond to determine which path is picked. The correct notation for what you are describing would be a solid line which generates multiple activation tokens on exit. The merge should also be a solid line as execution continues when all inputs have triggered. The way you have it execution will continue after only one activity completes.
I was thinking exactly the same, that parallel activities should be joined by a solid line. So, what is the truth?
Silvana Donato See the official specification of UML 2.0 (10 years old and I suppose Derek used 2.0 as a shortcut for 2.x), 12.3.30 on fork nodes (the fat black bars). Those are for concurrent flows. Derek is wrong.
Peter Kelley Yeah, this is all a bit confusing. But looking at the specs it seems that the fat bars are called forks for outgoing lines and joins for incoming. Accordingly, the diamonds are called decisions for outgoing and merges for incoming. So, technically what you called a "merge" should be a "join". Just to avoid confusion. =)
Peter Kelley Yeah, this is all a bit confusing. But looking at the specs it seems that the fat bars are called forks for outgoing lines and joins for incoming. Accordingly, the diamonds are called decisions for outgoing and merges for incoming. So, technically what you called a "merge" should be a "join". Just to avoid confusion. =)
You're very welcome. Thank you :)
Thank you :) This teaches about activity diagrams, but more importantly it teaches how to solve problems
In this tutorial I'm using UMLet because it is free and identical on every OS. In the real world I use a paper and pencil or a whiteboard.
That's ok. Always feel free to ask questions
Thank you :) What are you looking for? The Umlet file?
Yes that is true, but I'm not sure what you are referring to in the video?
Hey Derek Banas,
Nice video couple of stuff I would like to point out. The merge and fork you are showing is actually junction nodes (however your depiction is correct). Merge and fork actually is a rectangular black thick line, the arrows differentiate which is fork and merge. I use umlet a lot hence I know the differences.
2:33 The words "All at the same time" sound confusing here - does it mean that all actions must be performed at the same moment of time or is it just used as kind of "AND" logical operator which waits until all the actions get done and only after that it goes on?
I've never been into the uml tools that translate into code. I didn't find them useful and also they are extremely expensive. What tool are you using?
@1:28 Isn't this supposed to be a decision? And when the two lines recombine it should be a merge. Anyway that's what I learned.
I think the ones who disliked this video are the ones who make videos themselves but got jealous of Derek's videos haha. I just started learning UML Diagrams yesterday and I already learned so much in only two videos.
That's funny 😁 I'm happy I could help
awesome. 2 follow up Q's:
1. As an engineer, is is crazy to expect business people to provide activity diagrams? (As opposed to "umm.... just make it work by next month")
2. Why do you sound EXACTLY like Ed Helms?
I very much enjoy the random aggressive inflections you have throughout this video
Thank you :)
Reading 3 UML books from the library is not even as 50% of this video
thankyou sir !
Thank you for the compliment :)
I agree this is well put together. Seems like those big tech bibles are mostly self promotion books from what I can see. You have to do a lot of reading before you get into anything useful.
Thank you :) search for UmLet
1:29 isnt that a decision node, rather than a merge node?
UMLet is the name. It is free and works on every OS
wish i had known of these video series when i was still studying at the university... this is a 100x more enjoyable than i remembered :D
+Lyndon Michael Bibera Thank you :) I'm glad you liked it.
This tutorials were what I was always looking for !! Thanks a lot Derek, Coding is not much a big problem for me but I always struggled when I was asked to develop something from scratch, a lot of back and forth development cycles messes the whole project. Now I know how to proceed for new projects from scratch !
I'm very happy that I could help with this. Yes there is a big difference between writing simple programs and large professional ones. I couldn't imagine how I'd make a large application without UML.
what kind of prog. lang. you always use invinciblekd?
Abdulbarr Othman I'm primarily a c++ developer but now shifting slowly to Java !
Thank you :) I'm working to make videos easier to follow
You're very welcome :) sorry about the voice. I get that from constant allergy problems
Thanks so much Derek. This is very simple for someone who hasn't done any use cases.
@Peter and Silvana, indeed, I'd use a fork/join for that. But as far as I remember activities after a fork would not be executed necessarily at the same time (as the author states in his example) as the only condition to 'join' after the 'fork' is that all the activities are completed, whenever it is.
Fabio D'Amico Yeah, it's representing concurrency, not parallelism.
Whose point of view activity diagram usually based on? User or system? Thanks
really helpful better than my lecturer
I'm very happy that you liked it :)
i think to tell my teacher to show the class your videos,it's better than her teach
+a1m2a3l Thank you for the compliment :)
I am actually watching this for a university course. He's listed it as something we should watch. The best part is, I can stay awake while you talk.
Derek is our Internet Professor who teaches us how to Internet.
Thank you very much :) I greatly appreciate that!
Haha I actually studied this in uni last year so just going over your videos for next year since it's faster than going through my books & notes ;)
A detailed concept of activity diagrams is provided in this lecture.
Hello Derek, Guard conditions are shown for if..else block, but how do i draw the diagram for if..elif...elif..else case
Nowadays I watch your Java tutorials. Those tutorials are awesome. Thanks for them.
Thank you :) It was fun to make. I like zooming
Also at about 4:50 the object node has 2 outgoing flows. I believe that there is a default in this circumstance but I always forget whether it is a fork or a merge. Better to show what happens explicitly.
Peter Kelley No, that seems to be legit, at least for the actual 2.0 from 2005. Just looking at the specification.
Thank you :) It is very nice for you to say that.
THANK YOU MAN. TH-cam tutorials are more easier to learn by far.
TheTranshallow Your welcome :) I'm glad they help
Thanks for all these awesome tutorials :) Instead of having to read a bunch of ppt slides for an exam, I just listened to those tutorials and took some notes and I was done with my diagrams :) Subscribed to your channel. You seem to have many interesting tutorials!
Some people use notes while others don't. It normally depends on personal preference.
Sorry for the wait. Ill get to JEE topics as soon as possible
Don't worry. I hear about how outraged students are over the current system all of the time. I have the feeling that you'll see great changes in the education systems over the next few years. It is just to bad that current students will have to pay the price for that to happen. I've never been money motivated so I don't understand why so many people stand in the way of progress for a few extra bucks?
So what's the difference between the use case and this? i mean is one more of a preference thing or do you have to use them both?
Isn't the fork/join symbol those black horizontal or vertical bars?
Thank You very much
I'm happy to help :)
I made my own palette out of the basic shapes. You can save your own palettes. Sorry about the confusion
You must have one amazing brain if you can take the information in that fast. I'd guess that I have the smartest audience on TH-cam :)
You should do a video on how to actually make these, from downloading to complete diagram.
agree
I love this video, I watched it in 2015, I'm watching it not - it's simple and clear
Thank you :) I'm happy it helped
I'VE BEEN LOOKING FOR THIS PROGRAM THANNK YOU SO MUCH!
I'm happy I could help :)
Hey Derek, what is the difference between marking a node as a call activity node vs making a partition for that node where we explain it? Thank you!
i like how he starts his videos with "wellhellointernetandwelcometopart"
I don't like wasting time :)
This is my first time using UML. I found it very useful. Thank u Derek
+kinnaree patel I'm happy that I could help :)
What would be the best UML diagram to use when creating an app with a similar UI to Instagram? Followers. Small text posting. Not much customization like Facebook. Sweet and simple for now.
That's funny :) I'm very happy that I was able to help
Not to be a putz but at 1:26 you called the fork a merge. No big deal, the kind of mistake that we all make. Overall a very awesome tutorial, thank you for making them. :D
Sorry about that. I'm glad you liked it aside from that :)
Don't think that's a fork, it should be a decision, fork doesn't look like that.
watching this for my test today!
Isn't what you took as merge in the 1.30's minute a decision node?
Helpful and useful tutorial. Gotta finish my game design assignment with a good activity diagram ;)
Casey Lloyd Thank you :) I'm glad I could help
Does 1 use case equals 1 activity diagram? Would that be correct?
Thank you :)
Very helpful, clear, simple and objective explanation (as always).Derek, thank you for help me revise, improve and learn so many important concepts in diverse subjects.
Ana Souza Thank you :) You're very welcome
why reject account is merge? is it better for that action is go directly to final node??
Hi Derek. Fork and Guard seem very, very similar. Which condition would you use for, say, a login activity? They both seem like they would fit...
Just noticed from the previous comments that u were using UMLet as a mac user, thanks again :)
adi hamshari I always try to use tools that are free and available on every OS.
Still not sure how and when to use these. Would be great to see you breakdown a simple coding problem into UML Acitivity diagram and then code.
Don't we use a straight line for the fork purpose? I am a bit confused.
Are you sure about what you said over that Vertical Fork / Join (what you called partition - 7:54)? Wouldn't it be used when 2 different operations would work at the same time? (sorry about my english...)
You deserve many,many more likes and subscribes
Cuan Otto Thank you :) I'm doing my best to improve so more people find the videos useful.
i love listening to this guy saying "merge"
What is a swimlane? Can you explain it with an example?
Awesome videos as always! Watching it at a rate of 1.5 makes it even more quicker :D
great job! i watched many of your UML videos and they all GREAT! thank you for uploading them :)
Hi.. I found it very helpful. But i couldn't get idea about using partitioning in class diagrams. DO you have a referencefor that? Thanks
Thank you very much for your videos and efforts to explain.
Hi Derek. Excuse my ignorance but, how do you create a guard condition in UMLet?
I just draw everything by hand. I have links to my custom drawings on my site.
How do I create the interruption region onto my UMLet??
this is the hardest part of coding for me because its so freaking boring, your video was actually fun to listen to though!
I'm happy it helped :) Yes UML is boring, but it saves so much time on debugging
Thank you for sharing Derek! Although some information flies by really fast, you're easy to follow and fun to listen to!
+Christian Slijngard You're very welcome :) I do my best to keep it interesting.
After eight years this is still useful
I'm very happy to hear that I helped :)
Do we need to put pink notes to my activity diagrams or you just put it to your diagrams to make us understand ?
Excellent tutorial series. Thank you very much :)
Debopriyo Web Thank you :) You're very welcome
what kind of tool do you use to draw UML diagram?
well explained. just I think you forgot to mention that the partition also can be used in the case of multiple actions happening for example if passenger verified at the check-in counter, the boarding ticket will be provided and at the same time luggages will be collected.
Thank you :) Yes good point
Its quite confusing in using activity diagram to model use case diagram visually. Thanks to your video, I got it crystal clear :)
Thank you :) I'm glad I could help