Teach yourself Unified Modeling Language (UML) / PDF

Teach yourself Unified Modeling Language  (UML)

  What is UML?

    UML: Unified Modeling Language

•An industry-standard graphical language for specifying, visualizing, constructing, and documenting the artifacts of software systems, as well as for business modeling.

•The UML uses mostly graphical notations to express the OO analysis and design of software projects. 

•Simplifies the complex process of software design

      Why UML for Modeling?

•A diagram/picture = thousands words

•Uses graphical notation  to communicate more clearly than natural language (imprecise) and code(too detailed).

•Makes it easier for programmers and software architects to communicate.

•Helps acquire an overall view of a system.

•UML is not dependent on any one language or technology.

•UML moves us from fragmentation to standardization.

Types of UML Diagrams

 Use Case Diagram: capture requirements. Clarify exactly

    what the system is supposed to do

    Displays the relationship among actors and use cases.  Different from traditional flow chart.

 Class Diagram: static relationships between classes.

     Describe the types of objects in the system and various kinds of static relationship that exist among them.

 Sequence Diagram:  Displays the time sequence of the objects participating in the interaction.

     

   Use Case Diagram(core components)

Actors:  A role that a user plays with respect to the system,including human users and other systems. e.g.,inanimate physical objects (e.g. robot); an external system that needs some information from the current system.

•A use case is a single unit of meaningful work.  E.g. login, register, place an order, etc. 

•Each Use Case has a description which describes the functionality that will be built in the proposed system.

     E.g. for use case “order title” , a brief description: This use case receives orders from employee or supervisor, then return the ordered title......     

 System boundary: a rectangle diagram representing the boundary between the actors and the system.

Use case: A set of scenarios that describing an interaction  between a user and a system.....

Teach yourself Unified Modeling Language  (UML)