I'm new to using Sequence Diagrams, and I'm trying to find references but too many things make me ambiguous. There are a number of questions that I will ask about this problem.
From this references Ref1 and Ref2 I see a difference between Image1 1 and Image2 . For image1 he use MVC method, and for image2 he just pass it to database, and last i found this image on google he using boundary, but on PowerDesigner i dont see boundary icons
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Can you explain to me the difference between the three images?
Which should I use to create a login sequence diagram? In my case I will make "Web-based Monthly Report Archiving"
Can you give me a reliable reference for making Sequence Diagrams?
I always recommend reading some book explaining how to model system using UML. It makes things easier and you can find some on-line.
Ad1.
Sequence diagram is a method of showing the interaction in a specific sequence but it does not assume anything about methodologies or standards used during modelling. MVC is a standard unrelated to UML creating some best practices about how to design systems. Whether you use it or not is up to you (unless you're constrained by e.g. your company).
As already mentioned in a comment by bruno since MVC is not part of UML standard it does not have to be implemented in UML compliant tools. Yet since it's quite popular you may find it in many tools anyway.
Ad2.
It's up to you and your design decisions.
Ad3.
This page in general is not about suggesting sources for general things. As already mentioned above I would recommend reading some good book about modelling in general. My standard recommendations are Howard Podesva's "UML for the IT business analyst" and Craig Larman's "Applying UML and patterns". A direct reference about UML may be found on this excellent page but it will not tell you how to model or design, only how to depict your model properly on UML diagrams.
Related
I am working on a data science project for my 3-2 mini project. My project analyzes the performance of a country in the Olympics based on some attributes. But I am confused about the UML diagrams I should be using in my project.
There are some 15 UML diagram types out there. A sensible sequence of diagrams to be created depends on your approach.
If you'd like to create an analysis model that is a conceptual model of your problem domain then a sensible sequence of diagrams might be:
Usecase diagrams
Activity diagrams
Class diagrams
and if your project gets bigger you might need package diagrams.
If you'd like to create a design model that is a conceptual model of your solution domain then a sensible sequence of diagrams might be:
1. Component diagrams
2. Class diagrams
3. Sequence diagrams
4. Statecharts
In both cases a starting point is having a diagram for your system context. Some people like to mix component and usecase diagram features to denote a system context.
The aspects you might want to take into concideration of your diagram choices are:
syntax - how strictly would you like to follow the UML standard and what use does adhering to the standard have for you
semantics - what is your need - what do you want to document - and who needs to understand it
pragmatics - what is the best way to achieve your projects goal e.g. being efficient and effective
tool - what tools do you have at hand and are used and known to your peers - what can you afford to invest in keeping the tool infrastructure up
While your question is very broad, I could imagine that in view of:
My project analyzes the performance of a country in the Olympics based on some attributes.
you'll certainly need a class-diagram. Because the class diagram will clarify what kind of objects your software will manipulate (e.g. Olympic game, Participating countries, Teams, Athletes, Discipline, Competition), how they are related, and what attributes are associated with which each.
This will enable you to determine for the different analysis you want the access path to the relevant attributes. It will also allow you to find missing attributes, and to desing a convenient interface for the different classes.
You may also use other diagrams. But with the few requirements you've shared, it's difficult to guess which one and I do not want to do a lot of guesses. I could nevertheless imagine that a use-case diagram could help to give the big picture of who is going to do what with your software.
I was given a special task to learn and discuss about UML at work. I have a little background about the topic, though I'm not sure what area should I give more priority since UML has now multiple versions. Should I stick with the the UML first version and give an overview for the UML 2 instead? or should I focus more on the UML 2 since it's the latest version? I'm confuse since I'm not familiar with the difference of the two versions.
I need advise regarding the matter. Thank you in advance. Pardon if this question is irrelevant in this site.
It might be practically difficult to restrain to UML 1 just for the following reason: Nearly all available tools for drawing diagrams implement UML 2 since long time ago. So, each time when drawing some construct, you would manually have to check whether it was already available in UML 1.
The step from 1 to 2 was in a large part motivated by the software engineering hype named MDA (Model Driven Architecture) some 10..15 years ago. This was about generating software directly from the model. To support this, all model elements got defined via some formal semantics. Also, some model and diagram types got enhanced. Sequence diagrams were enriched to control structures to express control flows. Component and deployment diagrams got enhanced.
Now, apart from suggesting that it won't make much sense to go back to UML 1, I read from your question that you need to set priorities. That makes sense, as the definition of UML (1 as well as) 2 is quite lengthy, and you don't want to study every detail of it. So here are a few hints:
With object oriented technology everywhere around, class modeling is the central notion. So you should be familiar with classes, associations, aggregations, composition, inheritance, attributes, operations and their parameters and results, visibility of methods and attributes, abstract classes and methods, and interfaces.
Objects of a class change their states by application of their operations. A central, and sometime underestimated, type of model therefore is state modeling. Here, UML offers two partly redundant model and diagram types: State and activity models. You should get familiar with at least one of them -- switching to the other should then be not too difficult.
Most users of UML are quite fond of use case modeling. I'm not, as those use cases tend to lack either significance (if you constrain to naming use cases and actors) or structure (if you start documenting system data and functionality with your use cases). But the rest of the world will only accept you as an UML expert if you know them, so you won't be able to avoid them. Just before using them extensively, think about how to reach the DRY (don't repeat yourself) principle when describing a system via use cases.
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
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.
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).
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).
What are the steps to be followed when we start UML diagrams for new features or requirements?
I need the entire steps like
Identify the actor,
Identify the use cases,
like this etc....
What you need is some sort of methodology.UML doesn't come with any, because it is ment to be methodology independent. However, the authors of UML have created some methodologies, which heavily use UML. One of the methodologies, which is free, is Unified Process or UP for short. Try to look at that, there are plenty of books, which discuss UML and UP at the same time.
Create a simple model of the existing system, and a detailed model of the area you plan on working in. There are a number of different types of diagrams (activity, sequence, class, etc), you should use the ones most appropriate for the complexity of your system and its interactions with other components, systems, and people.
This is a very board expression. In general, I would start with Use Case diagrams and go from there. As Gabriel pointed out, there are entire books written on this and there is no one right answer. My personal favorites for Use Cases are:
Advanced Use Case Modelling
and
Writing Effective Use Cases
Take a look at Craig Larman's book "Applying UML and Patterns". That describes very accessibly how to use UML to tackle a problem (Use Cases, Class Diagrams, ...).
I need some sample UML diagrams for some project of medium complexity. Do you know of anywhere where I can find some? I don't need them for learning UML, but rather to test my application that I work on and that should be able to process UML diagrams.
It would suffice to have Class diagram, Package diagram and Component diagram, but those should all model the same system and should be consistent.
Here's an Oracle paper which contains the design of a Web Store application. This paper has all kinds of UML diagrams that one may want - Class, Component, Sequence, Data Model etc. It may not have package diagrams but, those are trivial.
Look at this site, they have nice examples in the product tutorials:
Enterprise Architect
Maybe you should be more concrete about what format you need... Also, it might be interesting to try out some reverse engineering from existing code.