I am very confused on what are these "components" should be. I am just starting with UML by the way. I don't know what components should be used or be place in the diagram. I've searched for definitions about these components and they are very hard to understand. Can you please explain it in a very simple way on what these components should be?
P.S.: This component diagram will be about a website. A planner website.
I can't post what I had in mind because I am a new user and new users aren't allowed to post images.
The way I think of them is as a large, logical, chunk of the functionality of a system; a bit like that which might be found in a single library or a .jar file. They tend to be associated more with software intensive systems distributed over multiple nodes (computers) and locations. They idea is that they interact, mainly, through well defined interfaces and that they can be replaced or "swapped out" with another component that will do the same job. An example would be changing to a different database management system, or updating some hardware drivers.
Components are used most in component and sequence diagrams.
I believe there is a debate as to what the real the differences between components and classes are. Both are specialisations of the concept of a classifier in UML
In your case —without knowing much about the specifics— you might have the following components with interfaces between them:
a web client component
a business/problem logic component or components
some sort of data management component.
At the end of the day though, you use the UML in whatever way works for you. A simple software project might not benefit at all from using component diagrams. It's up to each project team to define what context and level of abstraction they are working at and choose diagram types accordingly.
Related
I am complete beginner in uml and need to make diagrams to show use and structure of current information system in organization. They use one system for manufacturing and one for accounting, warehousing and HR. First I want to do use cases with description. First question is should i do it by module (each area of business they cover)?
Then i need a diagram to view connections between the systems. Is it okay to use component diagram or which diagram is more appropriate? If company uses Office 365 does it show in diagram? Also if system supports EDI should i also include it?
Thanks for help.
As always: It depends.
Use cases are about added value. If you are going to document a complex system it's a good idea to group things. For a company a grouping by organizations would be reasonable. Though there are often horizontal (single focus) and vertical (needed in multiple area) departments. If the focus is to "re-invent" you should probably decouple your view. Anyhow, finding real use cases is a difficult task. So during synthesizing them you will likely find out how to group them logically.
Starting with components is also a good idea. You can use component instances showing concrete uses (with locations shown via packages). These concrete components can be abstracted to general components so you known which different basic components are used (package them centrally). Interfaces between components can be shown by assembly connectors (those with socket/lollipop). Later you can detail important components using ports and interfaces. Other components can be left peripherally without more details. Whether EDI/Office are "important" depends. Include them generally and find out in discussions during analysis whether details are needed.
Firstly, I'm still quite new to UML; but, highly interested and am attempting to learn as much about it as I can.
With that said, I’m in a situation where I’m directed to assemble a ‘Context Diagram’. I feel as though I understand the concept of what a context diagram is and how to create one, so I think I’m ok there. Basically it is identifying the system and the components or actors it will interact with. It applies the focus on the system, and not the actors. Kind of like a Use case diagram, but not focusing on the actors. If I’m wrong, please tell me.
I read somewhere that Context Diagrams are not actually part of UML. I also read, somewhere, that, if you use a Context Diagram, it falls into the Component side of things. When I read about Domain models, it seems like it should be there.
For my current situation, I know a simple answer is to simply create the diagram and move on, as that is all that is required. But, for my interest to better understand and leverage UML, I know there is a right way and a wrong way. If I were in a case of a bigger project, what would be the right way?
Now here is where my question begins. I’m using Enterprise Architect, create my project, and start to create a model. Does it belong in a Domain Model or Component Model? What is the difference between these two? Or even more. As it is an aide to help identify requirements, should it go there? Or does is just simply depend on what and how I want to convey it?
The Domain Model is where you standardize the vocabulary that everyone on the project will use to communicate in a consistent manner. The development team are experts at software development, but they may not have any experience in the domain (e.g. banking, air traffic control, healthcare) in which they are being asked to work. So you get domain experts and modelling experts together to build a model that describes the domain, answering important questions like "how are account fees calculated?" and "how does a pilot know what route to follow?" and then this model is then passed to the development team to provide them with the important domain knowledge that they will need. I would use UML class diagrams to create a domain model.
A Context Diagram shows the system being modeled in relationship to external systems. It could show data flowing in from and out to external systems, modeled by a data flow diagram (not part of UML). It could show behavioral interactions between the system and external "actors", modeled by a UML use case diagram. It could show the system's physical connections to other systems, modeled by a SysML block diagram. Whichever you choose, it will be on page 1 of your design document, so choose wisely!
You (can) create context diagram by making any element composite. Then drag the element itself onto that diagram as link (not instance!) and highlight it by making the border a bit thicker. Finally insert related elements from the context menu (differs from EA version to version). Layout the diagram and now you have your element in the context.
A domain model is usually a class diagram showing the (business) domain on a higher abstraction level.
As you have said, Context Diagrams per se are not part of the UML spec. There are plenty of ways to do a context diagram, but the UML way is to use a Use Case diagram, with or without supporting narratives and scenarios. Start with this, which is a broad overview of different types of Context Diagrams. Then, investigate use case diagrams, use case narratives, and activity diagrams. If you need to go into more detail than a use case narrative can easily do, get into use case scenarios and sequence diagrams. Here is a pretty good use case narrative template (feel free to leave out sections such as "scope and level" if they are more than you need, and consider adding information about what triggers the use case and where you go when you finish it--these two are required for scenarios if you go that far).
Keep in mind that use case narratives and use case scenarios are often confused. (Some people will say that I am the confused one; I will invite you to judge the matter for yourself.) A narrative is an explanation of an entire (single) use case, and may be supported with an activity diagram. A scenario is an explanation of a single path through a single use case, and may be supported with a sequence diagram.
For example, a use case will generally have a basic flow of events, along with a number of alternate flows. The narrative describes the entire process. The basic flow and each alternate flow would each be a separate use case scenario.
I suspect that it's unlikely that you will have to get down to the level of use case scenarios. You will probably want to put a use case diagram together, and possibly prepare narratives and activity diagrams for each of the use cases in the diagram.
I would like to make a component diagram for a multiple robot coordination system.
I would like to show on the component diagram that the sub-component "Perception" of each "Robot" component communicates through an interface with each other. Indeed, the sensors of all robots are used in order to estimate the position/velocity of each robot, it is a cooperative sensing.
How can I do that ? Should I have an interface which would be both provided and required by the component "Robot" ?
Thanks.
For this type of system you are in position to use full power of UML and make really effective documentation. You will most likely need some (or all) of the following diagrams:
Component diagram - to show the "big picture" and the main parts of your system ant their interfaces and dependencies. Components are "black boxes" here and will be detailed in the following diagram
Composite structure - are perfect to open up the components and show their internal structure. You can take "black boxes" and their interfaces as kind of input to this work. Each component (except the external ones) should be modelled internally. This kind of diagrams lets you use the whole-part paradigm to model internal structure as a network of interconnected elements. Previously detected interfaces will be used here to show how they are actually implemented.
Class diagrams. If you need to further specify the elements of internal structure (their attributes, methods, associations, etc), this is the diagram to draw.
State machines. In embedded real-time systems, lots of classes are active and have states. Identify those classes (or even components) and use state diagrams to show their internal logic.
Sequences and interactions. These diagrams will help you to specify how different elements of your system work together to implement different scenarios.
Deployment diagram. As robot is a piece of hardware and these components run on it (or them, if there are more than one hardware node) you might want to show how the components are distributed over the hardware structure.
You could also have a look on timing diagram, relativelly new one, designed especially for real-time systems. It might come on handy if you need to express time restrictions, durations, etc.
If you are new to UML, I would recommend to start with components and deployment. They are relativelly easy to learn. As you feel understanding and need to express your ideas further, dive in the composite structure and states. And finally classes.
Have fun!
EXAMPLE
This is how I understand your model and its elements. This extends my comments.
Explanations are in comments and in the diagram notes.
A component diagram:
A component instances' diagram:
Note that the first diagram should be extended with the "connectivity rules" that define all valid connectivity possibilities. Is there only one CentralManager? Must each Robot be connected to CentralManager? Can a Robot talk to itself? And so on...
These and other questions should be modelled separatelly. On class diagrams benavior diagams, according to concrete details.
I am new to UML designing and read few articles on this. bit confused where to start..
Do i need to prepare all of the UML diagrams for a web application or is some diagrams are only essential for an application.
Thanks,
Start from Use Case - define, who will use your application(actors) and what they will do with it(use cases). Also, join close use cases into subsystems.
Component diagram - what main parts the system has and what info they will send to each other and if some part belongs to another
Go on with State machine - define what states will have your components and on what reasons can they change they states to other ones.
Deployment diagram will define on what PCs will these components live and about the connections/protocols/interfaces between them
Plan your user interfaces - now only the set of pages and frames and navigation between them and commands on them. Do not solve placing and colors yet
Class diagrams for every component
If for for some of your classes some instances are specifically important, use object diagram.
Draw the look of the UI
Code.
UML is there to help you. Pick only what you need. You'll hardly ever need all diagram types. Plus, it is convenient for the reader if he needs to know only a predefined UML subset to understand your draft.
Can anyone tell which UML diagram I should change if there is a slight change in the design of application.
The change is -> Earlier the application was using Active directory for authentication now I want to use the Membership provider instead.
I want to keep the change minimum in diagrams.
Thanks
Sounds like component diagrams or class diagrams. Check out the following topics and illustrations for VS 2010 Ultimate RC:
UML Component Diagrams: Reference at http://msdn.microsoft.com/en-us/library/dd409390%28VS.100%29.aspx:
A component diagram shows the parts of a design for a software system. A component diagram helps you
visualize the high-level structure of the system and the service behavior that those pieces provide
and consume through interfaces.
UML Class Diagrams: Reference at http://msdn.microsoft.com/en-us/library/dd409437%28VS.100%29.aspx
A UML class diagram describes the object and information structures used by your application, both
internally and in communication with its users. It describes the information without reference to any
particular implementation.
It will surely depend the diagrams at your disposal. Sound like a correction in one of the static diagram types, like the component diagram ...
This of course depends on how you structure your documents and your uml-diagrams.
In general I have a Conceptual model, Class Diagram and a Design Diagram which are diractly linked to the architecture. And then you should in most cases have System Sequence Diagrams and more. However, depending on how your structure is and to minimize the "changes" required.
I would suggest that you use something more generic for the parts that might be changed. Active Directory Authentication and Membership Provider Authentication is both Authentication methods, which means that you can, instead of displaying the whole sequence at the Authentication step, just use "Authentication".
Now, in the conceptual models and in the design + class diagrams, you will need to change and add some fields, tables or whatever is added. But it shouldn't matter if you need to add more or less, because the documents need to reflect upon your software as accurate as possible.
So, to minimize changes, use more generic types.