UML Behavioral Diagram

Activity Diagram

INSPIRING CREATIVE AND INNOVATIVE MINDS

Activity Diagram

• Activity diagrams describe the workflow behavior of a system

•  The diagrams describe the state of activities by showing the sequence of activities performed. 

•Activity diagrams can show activities that are conditional or parallel

INSPIRING CREATIVE AND INNOVATIVE MINDS

Activity Diagram Elements

Initial Activity: This shows the starting point or first activity . Final Activity: The end of the Activity

diagram

Represented by a rectangle with rounded (almost oval) edges.

Similar to flowcharts, a logic where a decision is to be made is depicted by a diamond

Some activities occur simultaneously or in parallel. Such activities are called concurrent activities.

Initial Activity Final Activity

Activity

Decisions

Concurrent Activities

INSPIRING CREATIVE AND INNOVATIVE MINDS

Activity Diagram allow to model Decisions

act Customer Process

Customer EntersWeb site

User Logs In

UserValidation

Rejected

View BookStore

Select Book for Purc hase

Add to Shopping Basket

View Shopping Basket

Commit Order

Supply Credit Card Deta ils

Confirm Purchase

Credit Card Problems

Close Order

Credit Check

Items De livered

Order Complete

Customer Process

Decision

INSPIRING CREATIVE AND INNOVATIVE MINDS

Activity Diagram can model concurrency

act Credit Card Problem

StaffContactClient

Order

Phone Client

Update on Credit Ca rd

Accept Order

Order

Cancel Order

Check Credit Card

Process Credit CardDeliv er Goods

Check Stock

Upda te M ail Order

ActivityFinal

Inva lid

Valid

Out of Stock

In Stock

Credit card problem Synchronization

Splitting

Synchronizationof multiple activities

Splitting the flow of control into multiple threads

INSPIRING CREATIVE AND INNOVATIVE MINDS

Exercise

Activity Diagram

Draw an activity diagram that represents the making of a cup of tea.

The initial three activities are Fill kettle with water, Find cup and Find tea bag and they may be performed in parallel. When the Find cup and Find tea bag are completed the activity Place tea bag in cup

can start. The kettle must have boiled and the tea bag must have been placed in the cup before the activity Add water to cup can begin. If milk is required then activity Add milk should be performed.