Systems Analysis and Design Chapter 4

ternary association

an association between exactly three distinct types of things

n-ary association

an association between n distinct types of things

unary association

an association between two instances of the same type of thing

association class

an association that is also treated as a class; often required in order to capture attributes for the association

compound attribute

an attribute that consists of multiple pieces of information but is best treated in the aggregate

identifier or key

an attribute the value of which uniquely identifies an individual thing or object

binary associations

associations between exactly two distinct types of things

domain classes

classes that describe objects from the problem domain

multiplicity constraints

the actual numeric count of the constraints on objects allowed in an association

inheritance

the concept that specialization classes inherit the attributes of the generalization class

problem domain

the specific area (or domain) of the user's business need (or problem) that is within the scope of the new system

subclass

the subordinate or more specialized class in a generalization/specialization relationship

superclass

the superior or more general class in a generalization/specialization relationship

data entities

the term used in an ER diagram to describe sets of things or individual things

camelback notation or camelcase notation

when words are concatenated to form a single word and the first letter of each embedded word is capitalized

class

a category or classification of a set of objects or things

domain model class diagram

a class diagram that only includes classes from the problem domain

concrete class

a class that allows individual objects or instances to exist

abstract class

a class that describes a category or set of objects but that never includes individual objects or instances

class diagram

a diagram consisting of classes (i.e., sets of objects) and associations among the classes

entity-relationship diagram (ERD)

a diagram consisting of data entities (i.e., sets of things) and their relationships

semantic net

a graphical representation of an individual data entity and its relationship with other individual data entities

cardinality

a measure of the number of links between one object and another object in a relationship

multiplicity

a measure, in UML, of the number of links between one object and another object in an association

whole-part relationship

a relationship between classes in which one class is a part or a component portion of another class

noun technique

a technique to identify problem domain objects by finding and classifying the nouns in a dialog or description setting

brainstorming technique

a technique to identify problem domain objects in which developers work with users in an open group

relationship

a term that describes a naturally occurring association between specific things, sometimes called an association

association

a term, in UML, that describes a naturally occurring relationship between specific things, sometimes called a relationship

generalization/specialization relationship

a type of hierarchical relationship in which subordinate classes are subsets of objects of the superior classes; an inheritance hierarchy

aggregation

a type of whole-part relationship in which the component parts also exist as individual objects apart from the aggregate

composition

a type of whole-part relationship in which the component parts cannot exist as individual objects apart from the total composition

attributes

descriptive pieces of information about things or objects