IT 510 Ch 6 Flashcards
Activity diagram
A diagram that resembles a horizontal flowchart that shows the actions and events as they occur. Activity diagrams show the order in which actions take place and identify the outcome.
Attribute
A single characteristic or fact about an entity. An attribute, or field, is the smallest piece of data that has meaning within an information system. For example, a Social Security number or company name could be examples of an attribute. In object-oriented analysis, an attribute is part of a class diagram that describes the characteristics of objects in the class. Also known as a data element.
Cardinality
A concept that describes how instances of one entity relate to instances of another entity. Described in entity-relationship diagrams by notation that indicates combinations that include zero or one-to-many, one-to-one, many-to-many.
Child
In inheritance, a child is the object that derives one or more attributes from another object, called the parent.
Class diagram
A detailed view of a single use case, showing the classes that participate in the use case and documenting the relationship among the classes.
Encapsulation
The idea that all data and methods are self-contained, as in a black box.
Focus
In a sequence diagram, a focus indicates when an object sends or receives a message. It is indicated by a narrow vertical rectangle that covers the lifeline.
Inheritance
A type of object relationship. Inheritance enables an object to derive one or more of its attributes from another object (e.g., an INSTRUCTOR or object may inherit many traits from the EMPLOYEE object, such as hire date).
Instance
A specific member of a class.
Lifeline
In a sequence diagram, a lifeline is used to represent the time during which the object above it is able to interact with the other objects in the use case. An X marks the end of a lifeline.
Message
An object-oriented command that tells an object to perform a certain method.
Method
Defines specific tasks that an object must perform. Describes what and how an object does something.
Object model
Describes objects, which combine data and processes. Object models are the end product of object-oriented analysis.
Parent
In inheritance, a parent is the object from which the other object, the child, derives one or more attributes.
Polymorphism
The concept that a message gives different meanings to different objects (e.g., a GOOD NIGHT message might produce different results depending on whether it is received by a child or the family dog).
Relationships
Enable objects to communicate and interact as they perform the business functions and transactions required by a system. Relationships describe what objects need to know about each other, how objects respond to changes in other objects, and the effects of membership in classes, superclasses, and subclasses.
State
An adjective that describes an object’s current status (e.g., a student could be a CURRENT, FUTURE, or PAST student).
State transition diagram
Shows how an object changes from one state to another, depending on the events that affect the object.
Subclass
A further division of objects in a class. Subclasses are more specific categories within a class.
Superclass
A more generalized category to which objects may belong (e.g., a NOVEL class might belong to a superclass called BOOK).
System boundary
Shows what is included and excluded from a system. Depicted by a shaded rectangle in use case diagrams.
Use case
Represents the steps in a specific business function or process in UML.
Use case description
A description in UML that documents the name of the use case, the actor, a description of the use case, a step-by-step list of the tasks required for successful completion, and other key descriptions and assumptions.
