I drawing use case diagram for my club, but i not sure this is the correct way to say administrator can do anything and member only can view profile, update data only the data itself
I build diagram with gliffy, this is my diagram and json data (this is just another representation of the picture below).
In principle your drawing is ok. What is definitely wrong is CRUD. This is not a use case. The same goes for Search. A use case must have substantive and verb at least. It may have an object as well.
Another thing is <<include>> relation. Avoid it! What you're trying here is a functional decomposition. Use cases are synthesized. When it comes to a functional decomposition in the class design you may introduce a general package for searching or CRUD.
There are various approaches on how to draw UCs. I prefer to bind them to Business processes rather than actors, since actor is mostly just any user of the system with some access rights assigned.
In this case I agree with #Thomas Kilian that draw use cases like CRUD or Update member data is not very useful. In use case diagram you are modelling interface of your system - buttons available for the outside world (actors) to press. Update member data is not visible outside so why to model it in Use Case diagram?
Related
I have seen examples of people representing CRUD use cases in use case diagrams as "Manage X", but I wanted to know whether I can use a generalisation like the one in the screenshot to group many of them.
My intention is that "manage item" applies to the current catalogue being browsed. Would this be fine?
Use case diagram:
Yes, you can use a generalization to convey the intent that the actor manages items, and that items can be of different kind.
But your diagram looks very detailed and appears to be more a user interface model rather than a real goal-oriented use-case. I.e it describes more the “how” than the “what”. This is not forbidden according to the UML specifications, but not advised, as it leads to complex diagrams, distracts the modeler from the user goals, and leads to a premature design of a user-interface, whereas other modeling techniques are better suited to ensure an optimal user experience.
See also this question, that addresses similar concerns but at a lower level of abstraction.
P.S - Unrelated thoughts: The diagram might create ambiguity, since it suggests on one side that browsing is specialized by types of items (browse X and browse Y), but at the same time it suggests that any browsing can be extended with managing any kind of items (manage X, manage Y). This could be one more symptom that the use case was created with some class design in mind and not centered on user goals
Edit:
Final outcome based on suggestion given by #qwerty_so
This is my use case diagram for View Repository in Source Code Management System.
This system is part of Project Management System.
The system is similar to GitHub, user can select project.
And it will display a list of repository for the project.
User can click a repository to view its details such as file tree and repository information.
Finally, user also can click the file in the tree to view its content.
Is my use of use case generalization correct?
Below use case is the previous version, I learnt that using use case diagram to model process is incorrect (Seidl et al., 2015, p. 37).
Seidl, M., Huemer, C., Kappel, G., & Scholz, M. (2015). UML # Classroom: An Introduction to Object-Oriented Modeling. Cham: Springer International Publishing.
Well, let me just ask a question: can you abstract added value? The only case where that is true is called franchise. So what you did is to introduce a new abstract bubble to connected three concrete use cases with your actor rather than connecting the concrete bubbles directly. What for? Where is the added value for "View repository"?
For the abstract actor it's similar. There is no need to make User abstract since it's already abstract. All actors denote roles, not real things. You can just leave that abstract keyword away and it would not change any semantics.
What often happens (and you are on that way) is that people start functional decomposition rather than synthesizing use cases. Use cases are about added value a system under consideration delivers to its actors. That's just it. Just present these added values. I know it's difficult for techies, but stick to that.
As always I recommend to read Bittner/Spence about use cases.
in my opinion, one use case is one scenario. since we have to make a scenario for every use case model drawn in the diagram, so one use case must have specific pre-condition and specific post-condition but only have one main or basic flow. Use case might have few alternative flows, that are illustrated in extends relationship. while include relationship is used to avoid repetition in several scenarios in main/basic flow of several use cases.
In an use case I have two Actor/user:
Patient
Expert
Both of them can do create/view/edit on patient profile. Expert can do them on all profiles,but patient can effect only on him/her profile.
I have to keep diagram clear and avoid from repeating the same things. Now I want to know is there a way to draw create/view/edit once but describe patient's limitations? Or it may be my mistake and it is better to use another diagram to describe limitations of actors? Sorry,but I am new by UML.
In the UML Use Case diagram there is (as far as I know) no built-in way to visually capture constraints. You can show then using the invaluable note symbol:
Although you can model the access right policies using some simple means:
realistic user access rights management will be probably implemented using access tokens, authentication, authorization and all this stuff delegated to another (complex and reliable) system component providing some kind of CanAccess(who, what, CRUD): boolean service to the "system".
In order to capture the various limitations you would typically put them into the precondition part of the Wikipedia: Use case narrative.
In the UML model the limitations would map to constraints and guard conditions shown in the behavior diagrams describing the use case.
See also:
chapter "Describing Use Case Behaviors" in uml-diagrams.org: UML Use Case
A use case diagram is not meant to show the permissions that each actor has to perform particular operations. It is meant to show what the system has to do and who it has to do it for.
In this case, I'd say you have only one kind of actor for this use case diagram: User. And you have the use cases: "User Creates/views/edits".
The exception would be if the Create operation of an Expert is different from that of a Patient (in a way that would be visible on the use case diagram). For instance, if "Expert Creates" also has to perform "Expert Sends Email", then that would be a reason to consider two separate actors.
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.
On a Use Case diagram can you show things that an actor cannot do, for example because they won't have permissions to do it?
Or is it just implied due to the fact that they won't have a line joining them to the particular use case?
If the Use Case you are diagramming is the case where an actor attempts to do something that is not permitted and is then denied, then yes, I would show it.
Otherwise, I would stick to only including things that are actually part of the use case.
No. An Actor would be connected to everything that he can do. If the Actor can't do it, then it's not shown.
This is what alternate paths are for. The basic path (a.k.a. happy path) will show what happens when the correct Actor initiates the Use Case. In the alternate paths you can show what happens if the wrong Actor attempts to initiate it.
You might model Role actors that can do the task. You could then have another use case that has the original actor attempting to acquire the given Role.
IMHO this question and most of the answers give a wrong impression about the way use cases should be used.
Use case was intended as a requirements technique that uses natural language. It is most and quite effective that way.
It can be a thoroughly destructive technique when it is combined with too much UML/modeling. Structured modeling of use case texts for example by modeling main and alternative flows using UML Activity Diagrams is a tried and tested way for example to create Use Cases of Mass Destruction.
A use case diagram can be useful but we should remember the purpose of use case as a technique which is first and foremost to identify the user goals a system should support. Subsequently we can capture more details using natural language in use case texts using main flow, alternative flows etc.
Using diagramming tools we can visualize some simple information:
- For each user goal we can create model element type Use Case.
- Show system boundary using a box for the system with use case elements in it.
- Create a relationship between actor and use case to show the actor has a particular goal against the system.
Keeping an up-to-date list of actors mapped to goals is however of secondary importance. Doing a stakeholder analysis, drawing up lists of actors is a means to identify the users goals. After user goals have been identified it is strictly speaking not longer necessary to keep the lists of actors around.
If we are asking questions about how to put user permissions in a use case model we are most likely trying to capture too much information. We should abstract model elements away so that the model does not try to answer/capture these type of detailed design questions.