UNIFIED MODELING LANGUAGE

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What Is a Model?

. A model is “a complete description of a system from a particular perspective.” A model is a simplification of reality.


Why Model?

.Modeling achieves four aims:
-Helps you to visualize a system as you want it to be.
-Permits you to specify the structure or behavior of a system.
-Gives you a template that guides you in constructing a system.
-Documents the decisions you have made.
.You build models of complex systems because you cannot comprehend such a system in its entirety.
.You build models to better understand the system you are developing.

Four Principles of Modeling


.The model you choose influences how the problem is attacked.

.Every model may be expressed at different levels of precision.

.The best models are connected to reality.

.No single model is sufficient.


The UML Is a Language for Visualizing


.Communicating conceptual models to others is prone to error unless everyone involved speaks the same language.

.There are things about a software system you can’t understand unless you build models.

.An explicit model facilitates communication.