DiagramsClass, Sequence and UML Model

Has actors and use cases

Use Case

Actors - entities whose behavior appears in the "Actor's Actions" column,

*the entities whose behavior appears in the "System's Response" column are also actors

Use case - sequence of actions that provide something of measurable value to an actor

Actors /Use cases

Example

Use Case

Example

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Class Diagram

UML Model

A UML diagram that depicts:◦ interactions between objects.◦ how the business currently works by showing how

various business objects interact. Purpose:

1. Model flow of control2. Identify synchronization3. Illustrate typical scenarios

Sequence Diagram

The focus is less on messages themselves and more on the order in which messages occur.

The diagram conveys this information along 2 dimensions: ◦ the vertical dimension shows, top down, the time

sequence of messages/calls as they occur, ◦ the horizontal dimension shows, left to right, the

object instances that the messages are sent to.

Elements

Example I

Creating sequence diagram

read them from top to bottom. As time increases, it depicts events

happening in the system, Also shows how various parts of the system

react to each other.

Steps

Purchase order

Example

MHC - system

Encoding data sequence diagram

ATM Sequence Diagram

Sequence Diagram (Transaction)

Creating a new event in calendar

Sequence diagram

These illustrate the dynamic nature of a system by modeling the flow of control from activity to activity.

An activity represents an operation on some class in the system that results in a change in the state of the system.

Activity Diagram

Example

Another Example

depict the various states that an object may be in and the transitions between those states.

State Diagram

Define states – condition or situation Describe state – add more information on

each state Describe Transitions – join with arrows Define transition triggers – define events Define guard/Constraints – set constraints

on the transition triggers

Steps to draw state diagram

State diagram for bank amount

Example

Weather station state diagram

The Deployment Diagram helps to model the physical aspect of an Object-Oriented software system.

It models the run-time configuration in a static view and visualizes the distribution of components in an application.

Generally, it involves modeling the hardware configurations together with the software components that lived on.

Deployment diagram

For a simple reservation system

Example

A Communication diagram models the interactions between objects or parts in terms of sequenced messages.

Communication diagrams represent a combination of information taken from Class, Sequence, and Use Case Diagrams describing both the static structure and dynamic behavior of a system.

Communication diagrams show which elements each one interacts with better, whereas, sequence diagrams show the order in which the interactions take place more clearly.

Collaboration/communication Diagram

Example