DEV475 Mastering Object-Oriented Analysis and Design with UML ...

DEV475 Mastering Object-Oriented Analysis and Design with UMLWhat Is Abstraction?What Is Abstraction?• The essential characteristicsof an entity that distinguish itfrom all other kinds of entities• Defines a boundary relative tothe perspective of the viewer• Is not a concrete manifestation,denotes the ideal essence ofsomethingMastering Object Oriented Analysis and Design with UMLCopyright © 2003 Rational Software, all rights reserved 16Abstraction can be defined as:Any model that includes the most important, essential, or distinguishing aspects ofsomething while suppressing or ignoring less important, immaterial, or diversionarydetails. It is the result of removing distinctions so as to emphasize commonalties.(Dictionary of Object Technology, Firesmith, Eykholt, 1995)• Abstraction allows us to manage complexity by concentrating on the essentialcharacteristics of an entity that distinguish it from all other kind of entities.• An abstraction is domain - and perspective - dependent. That is, what isimportant in one context, may not be in another.• OO allows us to model our system using abstractions from the problem domain(for example, classes and objects).2 - 16