Introduction to the Unified Modeling Language. More information can be found at https://www.spiraltrain.nl/course-uml-overview/?lang=en

1. UML Overview

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Course Schedule
• UML Introduction
• Use Case Modeling
• Structural Modeling
• Interactions
• State Machines
• Activity Graphs
2
• What is UML?
• Modeling Reasons
• UML History
• UML Design Goals
• UML Diagrams
• UML Views
• Use Case View
• Logical View
• Component View
• Deployment View
• Notes and Adornments
• Stereotypes
• Tagged Values
• Contraints
• System Sequence Diagrams

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What is UML?
• Unified Modeling Language for modeling systems :
• Mechanical systems, Electronic systems, Software systems
• Or a combination
• But also business processes
• A language that helps to cope with complexity of systems :
• Abstracts from uninteresting details
• Provides different, but related views
• Reveals large scale structure (architecture)
• A language that helps to develop software systems :
• Modeling the problem domain
• Specifying desired system behavior
• Describe implementation
• UML is not :
• A software development process like RUP or Scrum
• A programming language (models are not executable)
• A rigid prescription for modeling
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Modeling Reasons
• Provide structure for problem solving
• Improve communication with stakeholders
• Clarify requirements
• Experiment to explore multiple solutions
• Furnish abstractions to manage complexity
• Reduce time-to-market for business problem solutions
• Decrease development costs
• Manage the risk of mistakes
• Visual Modeling because graphics reveal data
• One picture can say more then thousands words
• 1 bitmap = 1 megaword
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UML History
• Number of OO methods increased to more than 50 in 1994
• The most notable and popular methods were :
• Booch's OOD , Jacobson's OOSE, Rumbaugh's OMT
• Fusion, Shlaer-Mellor, Coad and Yourdon
• No modeling language filled all needs completely
• This led to a Babylonian language confusion :
• Everybody invents and speaks his own modeling language
• Everybody has a different understanding of modeling concepts
• Tools all used a different language or dialect
• Interchange of models is not possible
• Around 1994 a comedy acted out in real life : The Three Amigos :
• Booch convinced methodologists Jacobson, Rumbaugh to join him at Rational
• This led to the birth of UML which incorporated the best of each OO method
• In 1997 first version of UML was released :
• It has been adopted by the OMG and is an ISO standard
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UML Versions
• Current version UML 2.5 was released in June 2015 :
• Added where XMI, XML Model Interchange, and OCL, Object Constraint Language
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Object Management Group (OMG)
• International industrial consortium with over 800 members :
• Member-controlled not-for-profit
• OMG wants to provide a framework for software development :
• Stimulate growth of object technology e.g. CORBA
• Increase interoperability of software of different vendors
• Reducing confusion by setting standards
• OMG’s mission since 1989 is to develop an architecture :
• For modeling and distributed application integration
• Guaranteeing reusability of components, interoperability and portability
• OMG Task Forces develop enterprise integration :
• Real-time, Embedded and Specialized Systems
• Analysis and Design, Architecture-Driven Modernization and Middleware
• OMG organizes for Internationalization and Unicode Conferences
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OMG Modeling and Metadata Specifications
• Specifications freely available and implementations exist :
• Includes several open modeling standards
• UML (Unified Modeling Language) :
• UML is a specification defining a graphical language
• Used for specifying, constructing artifacts of distributed object systems
• XMI (XML Metadata Interchange) :
• XMI is a model driven XML Integration framework for XML data and objects
• Rules by which a schema can be generated for a MOF-based metamodel
• OCL (Object Constraint Language) :
• Declarative language describing rules applying to UML models
• Precise text language providing constraint and object query expressions
• MOF (Meta-Object Facility) :
• MOF is a standard for model driven engineering
• Provides a type system for entities and interfaces to create and manipulate them
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UML Diagrams
• UML is constructed specifically to enable modeling of objects :
• Their structure, behavior and interaction
• Use Case Diagrams :
• Display boundary of system its major modes of use as observed by external actors
• Class Diagrams :
• Model the structure of objects
• Interaction Diagrams :
• In particular sequence diagrams and collaboration diagrams
• Show how particular use cases are realized through interactions between objects
• Statechart Diagrams :
• Model individual object behavior
• Component and Deployment Diagrams :
• Describe the physical implementation architecture
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UML Diagrams Overview
UML Introduction 10

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UML Diagram Characteristics
• UML offers a diagrammatic language-syntax :
• Models must satisfy the syntactic rules
• Language may be extended with new syntactic notions :
• Must be expressed in the existing ones
• New icons may be introduced using stereotypes
• Diagrams of model describe aspects (or views) of same system :
• Models must be consistent
• At any stage of modeling :
• Selected details may be added or omitted from the diagrams
• Models may be incomplete
• Models may be adorned with more information
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UML Views
• Use Case View :
• Captures mode of use of system as observed by external actor
• Use Case diagram is visual representation of such modes of use
• Logical View :
• Captures static and dynamic relationships between conceptual entities in a domain
• Logical View abstracts from their physical representation or implementation
• Class diagrams and object diagrams are used in the logical view
• Component View :
• Captures system’s physical packaging, such as program files and subsystems
• Component diagram is visual representation of components
• Process View :
• Captures dynamic behavior of a system
• State, activity, sequence and collaboration diagrams are used in the process view
• Deployment View :
• Description of the allocation of components to execution resources
• Deployment diagram identifies deployment modules
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Four plus One
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Use-Case View
• Use-Case Diagrams model modes of use of a system :
• Use Cases
• Actors
UML Introduction 14
Visitor
Staff
Patient
Person NormalUse
<<includes>>
<<includes>>
PressDoorButton
<<extends>>
EnterLiftCage
ExitLiftCage
Normal use of a
hospital lift

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Logical View
• Class Diagrams model structure of objects and relationships :
• Classes
• Objects
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Lift system
DoorButton Chime
sound()
Door
FloorRequestButton
Shaft
LiftCage
22 111010
11
Lift System (modeling structure)

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• Interaction diagrams model interactions between objects :
• Objects
• Messages
Logical View
UML Introduction 16
Lift System (behavior model)
DoorButton Chime
sound()
Door
FloorRequestButton
Shaft
LiftCage
22 11
1010
11
: Person
upButton : LiftCagefloorRequestButton: Door
press( )
doorIsClosed ()
press()
visit(j)
close()
pass
pass
visit(i)
open( )
atFloor(i)
atFloor(j)
open( )

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Logical View
• Statechart Diagrams model behavior of individual objects :
• States
• Transitions
• Events (messages)
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Opening
do: opening()
Closing
do: closing()
entry: detector.enable()
exit: detector.disable()
Closed
open()
stopClosing()
Open
after( closureTimeOut )
close()
Door model
(behavior)

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Component View
• Component Diagrams :
• Typical components:
— Executables
— DLL’s
— Packages
— Database tables
• Show component dependencies
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Building.java
java.awt
Building.html background.gif
Building.class Lift
JavaDevices Devices
appletviewer.exe

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Deployment View
• Deployment Diagrams :
• Show the physical distribution of components over processors
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or
CompA CompB CompC
Telemetry Node
Location of components
on nodes
Telemetry Node
CompA CompB

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UML Common Mechanisms
• Specifications
• Adornments
• Notes attach information to a model
• Common divisions
• Extensibility mechanisms
• Stereotypes extend the vocabulary of the UML
• Tagged values extend the properties of the UML
• Constraints extend the semantics of the UML
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Notes and other Adornments
UML Introduction 21
See http://www.spiraltrain.nl
for an example of this applet
embedded URL
See language.doc
for details about the language
implementation.
Consider using the factory design
pattern here. Emb 5/11/99
simple text
link to document
Client
bill.exe
report.exe
contacts.exe
Transaction
addAction()
removeAction
perform()
Exceptions
emptyTransaction
nosuchAction
resourceLocked
anonymous compartment
named compartment

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Stereotypes
• New kind of model element based on existing element
• Just like existing element but with extra semantics
• Defined when stereotype is defined
• Can be based on all kind of model elements and used in the same situations
• Predefined stereotypes enable adjustment model elements
• Representation of stereotypes
• Name as a string between angle brackets above the model element
• Also possible is an own graphical representation
• Most requested new model elements
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<<Actor>>
Customer
<<Exception>>
Overflow !
named stereotype named stereotype
with icon
stereotyped element
As icon
X-axis Position
Sensor
RS-485

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Tagged Values
• Properties of model elements :
• Name-value pairs, also called tagged values
• New tagged values can be added to hold additional information
• Any type of information can be attached to model elements :
• Method specific information
• Administrative information about progress
• Any other kind of information
UML Introduction 23
Instrument
{abstract}
{author=“HEE”}
{status= draft}
value : int
expdate : Date
Server
{processors = 8}
<<library>>
Trans.dll
{serverOnly}
tagged value
value of tag

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Constraints
• Specify conditions that must be true for a well formed model :
• Value constraints on class attributes
• Constraint on an association that communication is encrypted
• Constraint that only one association is active at a time
• Constraint modeling in UML :
• Free-form text between brackets
• More formally described by OCL (Object Constraint Language)
• A number of constraints are predefined in UML :
• xor, subset, overlapping, disjoint
UML Introduction 24
{subset}
Department
Person
member manager
**
1..* 1

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Summary : UML Introduction
• UML is a language for modeling systems :
• Mechanical systems, Electronic systems, Software systems
• UML is constructed specifically to enable modeling of objects :
• Their structure, behavior and interaction
• UML has four plus one views on particular system aspects :
• Use Case View, Logical View , Component View, Process View, Deployment View
• UML offers a diagrammatic language-syntax :
• Each view is described with view specific diagrams
• Models must satisfy the syntactic rules and must be consistent
• UML has following extensibility mechanisms :
• Stereotypes extend the vocabulary of the UML
• Tagged values extend the properties of the UML
• UML supports modeling of constraints :
• In free-form text between brackets or
• Formally in OCL (Object Constraint Language)
UML Introduction 25
Exercise 1
Getting Started