Dependency relationship in use case diagram

UML relationships in use-case diagrams

dependency relationship in use case diagram

In UML, a relationship is a connection between model elements. A UML Dependencies, Indicate that a change to one model element can affect another model. Create Use Case Diagram for describing the behavior of the target system from an A dependency is a relationship that signifies that a single or a set of model. The key to Include and extend use case relationships is to realize that, common with the rest of UML, the dotted arrow between use cases is a dependency.

The purpose of this action is modularization of behaviors, making them more manageable.

Reuse in Use-Case Models: >, >, and Inheritance

Use case B is extracted from larger use case A into a separate use case. Use cases B and C are extracted from larger use case A into separate use cases. When two or more use cases have some common behaviorthis common part could be extracted into a separate use case to be included back by the use cases with the UML include relationship. Execution of the included use case is analogous to a subroutine call or macro command in programming.

dependency relationship in use case diagram

All of the behavior of the included use case is executed at a single location in the including use case before execution of the including use case is resumed. Note, while UML 2. Including use case depends on the addition of the included use case, which is required and not optional. It means that including use case is not complete by itself, and so it would make sense to refer to the including use cases as abstract use cases.

UML Use Case Include

Neither of UML 2. The applicant is now considered to be a student. The registrar helps the student to enroll in seminars via the use case UC 17 Enroll in Seminar. The student pays the initial fee.

Use Case Diagram - UML 2 Diagrams - UML Modeling Tool

The system prints a receipt. The registrar hands the student the receipt. The use case ends. Include Dependencies Between Use Cases A second way to indicate potential reuse within use-case models exists in the form of include dependencies.

dependency relationship in use case diagram

An include dependency, formerly known as a uses relationship in UML v1. The best way to think of an include dependency is that it is the invocation of a use case by another one.

The blue test in Figure 2 presents an example of how you would indicate where the use case is included in the logic of the including use case. Similar to calling a function or invoking an operation within source code, isn't it? You use include dependencies whenever one use case needs the behavior of another.

Usecase Diagram Relationships - UML - Vijay S Shukla - Business Analyst Training

Introducing a new use case that encapsulates similar logic that occurs in several use cases is quite common.

For example, you may discover several use cases need the behavior to search for and then update information about students, indicating the potential need for an "Update Student Record" use case included by the other use cases. Why should you bother maintaining an "Includes" and an "Extends" list in your use cases? The answer is simple: Yes, it would be nice if everyone has access to the use-case diagram because it also contains this information, but the reality is that sometimes you use different tools to document each part of your model.

For example, your diagrams could be drawn using a drawing package and your use cases documented in a word processor. Some of your project stakeholders may have access to the word processor you are using, but not the drawing package.

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The main disadvantage of this approach is you need to maintain these two lists in parallel with the diagram, the danger being they may become unsynchronized. Inheritance Between Use Cases Use cases can inherit from other use cases, offering a third opportunity to indicate potential reuse.

Figure 1 depicts an example of this, showing that "Enroll Family Member in University" inherits from the "Enroll In University" use case. Inheritance between use cases is not as common as either the use of extend or include dependencies, but it is still possible.

dependency relationship in use case diagram

The inheriting use case would completely replace one or more of the courses of action of the inherited use case. In this case, the basic course of action is completely rewritten to reflect that new business rules are applied when the family member of a professor is enrolling at the university.

Family members are allowed to enroll in the school, regardless of the marks they earned in high school, they don't have to pay any enrollment fees, and they are given top priority for enrollment in the university. Inheritance between use cases should be applied whenever a single condition, in this case, the student is a family member of a professor, would result in the definition of several alternate courses.

Without the option to define an inheriting use case, you need to introduce an alternate course to rework the check of the student's high-school marks, the charging of enrollment feeds, and for prioritization of who is allowed to enroll in the given semester.

The inheriting use case is much simpler than the use case from which it inherits. It should have a name, description, and identifier, and it should also indicate from which use case it inherits in the "Inherits From" section. This includes any section that is replaced, particularly the pre-conditions and post-conditions as well as any courses of action.

dependency relationship in use case diagram