Activity, Collaboration, and
Component Diagrams
Philip Liew
Activity Diagrams
• Represent the business and operational
workflow of a system
• Shows activity, and event that causes
object to be in particular state
• Starting point
– First activity of the flow
• Activity
• Decisions
• Signals (input and output)
• Concurrent activity
• Final activity
Activity Example
Sequence Diagrams
• Depicts a sequence of actions that occur
in a system
• Captures invoked methods of objects, and
order of invocation
• Represents dynamic behaviour of system
Sequence Symbols
• Object is an instance of a class
• Name to the left of “:” is object
• Name to the right of “:” is class
• Arrows represent messages
Simple messages
Special message creating object
Special message destroying object
Message response
Sequence Diagram
• Horizontal object shows life of represented
• Vertical axis represents sequence of
invocation of object
Sequence Diagram Skeleton
Collaboration Diagram
• Sequence diagram is time ordered
• Like activity diagrams but shows
association with other objects in the
• Object
• Relation/Association
• Message
– Number represents order of
Component Diagram
• Represents Implementation perspective
• Reflect grouping of different design
elements of system
Component Elements
• Component
– Interacting objects within system
• Class/Interface/Object
• Relation/Association
Component Diagram Example
Deployment Diagram
• Represents physical relationships among
software and hardware components as
realized in running system
• Nodes represent computational elements
(i.e. processor, server, etc.)
Deployment Diagram Skeleton
Courseware Example
• Construct the design elements for a system that can be
used to manage courses/classes
• The organization offers a courses in areas such as
learning management techniques and understanding
different software languages and technologies
• Each course consists of a set of topics
• Tutors assigned courses to teach according to their
specialty and availability
• Publishes and maintains calendar of courses and
assigned tutors
• Course Administrators who manage content, assign
courses to tutors, and define schedule
Identify Actors
Course Administrators
Course Administrator is main actor
Use Case
• Manage courses
– View courses
– Manage topics for a course
– Manage course information
• Manage course assignments
– View course calendar
– View tutors
– Manage tutor information
– Assign courses to tutors
Use Case
Class Diagram
Activity Diagram
Sequence Diagram
Collaboration Diagram
Component Diagram

Sequence, Collaboration, Deployment