UML Elements : Use Case Diagram
In the Unified Modeling Language, a use case diagram is a subset of the behavior diagrams. The Unified Modeling Language will utilize the use case diagram as a graphical system which symbolizes use cases.
It must be noted that UML will not define the standards which will be used for the written format to denote these use cases, and many people make the mistake of thinking that this graphical system can be used to define the nature and function of the use cases. In reality, this graphical system can only give the most basic view of a use case or a collection of use cases. The use case diagram may also be confused with the use cases. While these two elements may be related, they are different.
One thing that separates the two is the fact that the use case is much more complex than the use diagram. The SysML will use the same notation that UML utilizes, and system engineers may also model the system level. It should also be noted that there is no format which specifically defines the use cases. Many people who are new to UML make mistakes when it comes to understanding the graphical notation of this system. While these graphical notations may have a certain degree of importance, in the end, they are nothing more than documentations of the use case itself. The actual value of a use case can be split into two categories, and these are the business task and the position of the context.
As far as a business task is concerned, the description will emphasize the value that is provided via the system, and this will be given to external parties which may include either humans or other systems altogether. The position of the context is also important because it can define the use case in relation to other use cases. When you’re dealing with a mechanism that is organized, there are a number of use cases that must be consistent to showcase a solid picture, and the ways in which the system behaves. For example, a basic understanding must be formulated among the user, owner, and the customer. Some developers may create supplementary specifications which can be used to gain important requirements. These requirements may exist outside of the boundaries of the use case definitions.
The Sequence and use case diagrams are both valuable in different ways. The use case diagram is powerful because it can define the function of a basic system, such as the restaurant example that I described earlier. The use case will always be symbolized by the ovals, as well as actors, which will be defined by stick figures. In the case of my restaurant example, only the chef actor can cook food, while the customer will have the ability to eat food and pay for it. A box can be used to define the limits of your system, and the use cases which are shown are a part of this system. It should also be emphasized that the interactions between actors will not be showcased on the use case diagram.