UML: Unified Modeling Language

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UML Unified Modeling Language

• L. Grewe

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History

• Graphic modeling language for describing
  object-oriented software
• Started in 1994
• Combined notations from 3 leading OO methods
• OMT (James Rumbaugh)
• OOSE (Ivar Jacobson)
• Booch (Grady Booch)
• Industry standard

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Why UML?

• Software larger complex
• Difficult to analyze
• Describe SW clearly
• Use Computer-aided software engineering (CASE)
  tools
• A picture is worth a thousand words..save time
  looking at and making visuals.

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What is UML?

• Specify Visualize Software via modeling
  language
• views
• diagrams
• relationships between classes

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UML Concepts

• Use case diagrams/studies
• Class Diagrams
• Instance Snapshots
• Sequence Diagrams
• .more (for complete understanding of UML take
  our SW Engineering course)

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UML Concepts.more
State Diagrams
State Diagrams
Class Diagrams
Use Case Diagrams
Use Case Diagrams
State Diagrams
Use Case Diagrams
State Diagrams
Use Case Diagrams
Object Diagrams
Use Case Diagrams
Sequence Diagrams
Scenario Diagrams
State Diagrams
Scenario Diagrams
State Diagrams
Collaboration Diagrams
Component Diagrams
Models
Component Diagrams
Scenario Diagrams
Component Diagrams
Scenario Diagrams
Deployment Diagrams
Statechart Diagrams
Activity Diagrams
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UML Use case study

• Use Case Studies to understand system and the
  stakeholders requirements.
• Uses concept of Actors
• Often serves some kind of role in the SW system.
  (e.g. customer, vendor, etc.)
• Define State Operations for each Actor
• Define Relationships between Actors

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Use Case Diagram

• Shows actors, entities and actions involved in
  one usage scenario
• Have a diagram and often corresponding
  description
• Can (often) have more than one for a software
  program

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Example Use Case Diagram

• use case buy_thing
• participants (Purchaser, Vendor, Thing)
• pre-condition
• vendor.possessions -gt includes thing
• purchaser.pocket gt thing.price
• post-condition
• vendor.possessions vendor.possessions - thing
• purchaser.possessions purchaser.possessions
  thing
• vendor.till vendor.till_at_pre thing.price
• purchaser.pocket purchaser.pocket_at_pre -
  thing.price

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UML Class Diagrams

• Classes are Graphically Represented with areas
  for
• Class Name, Class Variables, and Operations
• Properties, Responsibilities, Rules, Modification
  History, etc.

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Example Class Diagram

• BookTitle class
• BookTitle Instance

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Another Example Class Diagrams

• Here show class diagrams and associations between
  the classes.
• Associations (diamonds/arrows) show aggregations/
  compositions
• See class webiste and reading for more details.
• Classes Company, Department, Office,
  Headquarters, Person, ContractInformation,
  PersonalRecord

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Class Diagrams relationships Between Classes

• Association
• Permanent, structural, has a
• Solid line (arrowhead optional)
• Dependency
• Temporary, uses a
• Dotted line with arrowhead
• Generalization
• Inheritance, is a
• Solid line with open (triangular) arrowhead
• Implementation
• Dotted line with open (triangular) arrowhead

OR
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Associations w/ Navigation Information

• Can indicate direction of relationship
• Represented by solid line with arrowhead

Gas Pedal class knows about Engine class Engine
class doesnt know about Gas Pedal class
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Cardinality of Associations

• Some relationships may be quantified
• Cardinality denotes how many objects the source
  object can legitimately reference
• Examples
• ? 0, 1, or more
• 5 ? 5 exactly
• 5..8 ? between 5 and 8, inclusive
• 5.. ? 5 or more

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Example cardinality

• Says Bank to Branch is a 1 to many
  association.means a Bank can have many Branches,
  but, a Branch is associated with one Bank.

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UML Instance Snapshot

• Diagram that shows results of applying a use-case
  action.

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UML Use Case Sequence Diagram

• Scenario shows the sequence of events in a
  use-case.
• Here the use-case is ian applying for a job,
  where tony is the secretary and sue is the
  manager.

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Generalization

• Denotes inheritance between classes
• Can view as is-a relationship
• Represented by line ending in (open) triangle

Laptop, Desktop, PDA inherit state behavior
from Computers