3. Features of UML

A 'system' can be thought of as a number of smaller sub-systems joined together and interacting in some way. In OOP parlance a system is made up of a set of interacting objects.

A system can may be a purely physical thing such as a car or a purely abstract one such as a database or somewhere in-between such as a stock control system. UML supports the definition of all these kinds of systems. It is a flexible and robust way of depicting a system.

There are three main activities in creating a working system

1. Definition
2. Analysis
3. Design

UML helps with each of these activities.

UML includes

• A way of visually showing the overall architecture of the system
• A way of showing the same system from different points of view (abstraction)
• A standard graphical set of shapes representing generic objects within a system
• A standard way of documenting the attributes (data) of each object
• A way of defining functions / methods that can change the state of each object
• A way of showing how the objects interact with one another
• Making it possible to generate code directly from an UML diagram
• Making it possible to allow vendors to produce toolsets for developers