Unified Modeling Language

1
Unified Modeling Language

• a language for specifying, constructing,
  visualizing and documenting the artifacts of a
  software-intensive system
• also for Business Modeling and other non-software
  systems
• Authors Grady Booch, Jim Rumbaugh and Ivar
  Jacobson
• Stems out from Booch, OMT, OOSE (and others)

2

• History

Industrialization
Standardization
Unification
Fragmentation
Booch method
OMT
3

• Goals
• ready-to-use, expressive visual modeling language
• extensibility and specialization mechanisms to
  extend the core concepts
• independent of particular programming languages
  and development process
• formal basis for understanding the modeling
  language
• encourage the growth of the OO tools (CASE)
  market
• support higher-level development concepts such as
  collaboration, frameworks, patterns and
  components
• integrate best practices

4

• Outside the scope of UML
• Programming languages
• the UML is a modeling language, not programming
• its aim is not to capture all necessary
  constructs of programming languages
• Tools
• the UML defines a semantic metamodel, not an tool
  interface, storage or run-time model
• the UML documents do include some tips to tool
  vendors (implementation choices), but do not
  address everything
• Process
• the UML is intentionally process independent, and
  defining a standard process was not a goal of UML
• UML is a common language for priject artifacts,
  developed in the context of different processes

5

• Artifacts
• UML Semantics
• description of the UML metamodel, i.e. a model
  defining a language
• Abstract syntax
• Well formedness rules
• Semantics
• UML Notation Guide
• graphical notation and textual syntax of visual
  elements of the UML language
• UML Extensions
• language extensions for Objectory Process,
  Business Modeling, etc.

6
UML Generic mechanisms/Diagram elements

• Graphs and their contents
• Strings
• Name
• Label
• Keywords
• Expression (OCL Expression)
• Note
• Type-instance correspondence

7
Graphs and their contents

• UML diagrams
• are graphs containing nodes connected by paths.
• the information is mostly in the topology
  (exception a sequence diagram with a metric time
  axis)
• Graphical constructs used in UML notation
• icon, two-dimensional symbols, drawing paths
• strings

8
Graphs and their contents

• Invisible hyperlinks and the role of tool
• a notation may contain additional invisible
  hyperlinks that are not apparent in a static view
• a dynamic notation - out of scope of the UML
• Background information
• each appearance of a symbol may have its own
  presentation choices
• information presented in a textual or tabular
  format
• presenting tabular information is a tool
  responsibility (out of scope of UML)

9

• Strings
• a sequence of characters
• they map underlying model strings, although some
  strings may exist purely on the diagrams
• Example
• BankAccount
• integrate (f Function, from Real, to Real)
• Name
• a string, that uniquely identifies a model
  element within some scope
• a pathname names linked by a delimiter (e.g.
  )
• Example
• integrate
• MathPakMatricesBandedMatrix.dimension

10

• Label
• a string that is attached to a graphic symbol
• it is purely a notational term
• Example
• Keywords
• used to distinguish variations on a common theme
• general notation is keyword
• Example
• ltltstereotypegtgt

11

• Expression
• expressed as strings in a particular language
• the OCL is used within the UML semantic
  definition
• linguistic formulas yielding values
• Example
• BankAccount () (Person, int)
• i gt j and self.size gt i
• OCL Expression
• used to define constraints (within the UML
  metamodel itself)
• Example
• flight.pilot.training_hours gt flight.plane.minimum
  _hours
• company.employees-gtselect (title Manager and
  self.reports-gtsize gt 10)

12

• Note
• a graphical symbol containing textual information
• a notation for rendering constraints,comments,
  method bodies, and tagged values
• is a notational item
• Example

13

• Type-instance correspondence
• a major purpose of modeling is to prepare generic
  descriptions that describe many specific
  particular items -gt type-instance dichotomy
• in UML the type-instance distinction is shown by
  employing the same symbol and by underlining the
  name string of an instance element.
• Example

14
Generic mechanisms/Model management

• Packages
• may contain packages and ordinary model elements
• some packages may be Subsystems or Models
• the basis for configuration control, access
  control
• element can be directly owned by a single package
• stereotypes system, facade, framework, top
  package
• the visibility ( public, - private,
  protected)
• dependency between packages gt dependencies among
  the elements

15

• Example (of packages)

16
General extension mechanisms

• represents general purpose mechanisms that may be
  applied to any modeling element
• an extensibility device for UML
• Constraint
• Comment
• Tagged values
• Stereotypes

17

• Constraint
• represents semantic information attached to a
  model element - conditions to be maintained as
  true
• is shown as a text string in braces ( )
• a predefined language for writing constraints is
  OCL
• a user-defined constraint is described in words
  in a given language
• Stereotypes ltltinvariantgtgt, ltltpostconditiongtgt,
  ltltpreconditiongtgt
• Comment
• a text string attached directly to a model
  element.
• attaches arbitrary textual information to any
  model element
• Stereotypes ltltrequirementgtgt,ltltresponsibilitygtgt

18

• Example (constraints comments)

19

• Tagged values
• a mechanism to define new element properties
• a property is a value attached to a model element
• a keyword-value pair gt tag-value
• Example
• author Joe Smith, deadline 31-March-1997,
  status analysis or abstract
• Stereotype
• built-in extensibility mechanisms of UML
• a new class (subclass of an existing ) of
  modelling elements introduced at modelling time
• notation
• a key-word string (within guillemets,e.g. foo.)
• a special graphic icon

20

• Example (of stereotypes)

21
Static structure diagrams

• Class diagrams
• show the static structure of the model,
• contain classes, interfaces, packages,
  relationships
• also known as static structural diagrams
• are organized into packages
• Static object diagram
• a graph of instances
• an instance of a class diagram - a snapshot of
  the state of a system at a point in time
• shows examples of data structures

22

• Concepts to be discusssed
• Class
• Attribute and Operation
• Interface, Parameterized class, Utility
• Type vs. Implementation class
• Importing a package
• Object
• Bin, N-ary Association
• Association end, Aggregation, Composition,
  Multiplicity, Qualifier, Association class
• Generalization
• Dependency
• Derived element

23

• Class
• the descriptor for a set of objects with similar
  structure, behavior, and relationships
• represents a concept within the modeled system
• classes have data structure and behavior and
  relationships to other elements
• the name of a class has scope within the package
  in which it is declared gt the name must be
  unique
• Notation
• rectangle with 3 compartments
• name and general properties, attributes,
  operations
• a reference to a class gt Package-nameClass-name
  

24

• Example (of classes)

25

• Attribute
• is semantically equivalent to a composition
  association (the intent and usage is normally
  different)
• Notation
• visibility name multiplicity type default
  property-string
• visibility public, protected, - private
• property-string indicates property values, e.g.
• frozen - a nonchangeable attribute
• a class-scope attribute - underlined or preceded
  with
• multiplicity
• if absent an attribute holds exactly 1 value
• e.g. name 0..1 String (permits a distinction
  between the null value and the empty string)

26

• Operation
• a service that an instance of the class may be
  requested to perform
• Notation
• visibility name ( parameter-list ) return
  property-string
• parameter-list is a comma-separated list of
• kind name type-expression default-value
• kind is in, out, or inout, with the default in if
  absent
• property-string indicates property values, e.g.
• query - operation does not modify the system
  state
• sequential, guarded, concurrent
• abstract - the class does not implement the
  operation
• stereotype signal indicates that the class
  accepts the given signal (with operation name)

27

• Type vs. Implementation class
• Type
• is a specification of externally visible
  behavior of a set of objects
• Implementation Class
• defines the physical data structure and
  procedures of an object
• an object may have multiple Types but only one
  Implementation Class (which is fixed)
• the implementation of a type by an implementation
  class is modeled as the Realizes relationship
  (this implies inheritence of operations, not of
  structure)

28

• Example (of a type and impl. class)

29

• Interface
• is a specifier for the externally-visible
  operations of a class, component, or other entity
  (e.g. packages)
• does not have implementation
• may have generalization relationships
• Example

30

• Parameterized class Bound element
• Template
• the descriptor for a class with unbound formal
  parameters
• defines a family of classes (but, is not a
  directly-usable class)
• attributes and operations are defined in terms of
  the parameters
• Bound element
• templates parameters are bound to actual values.
• fully specified by its template (content may not
  be extended)
• Example

31

• Utility
• is a grouping of global variables and procedures
• attributes and operations are interpreted as
  being at class scope
• Example
• Metaclass
• is a class whose instances are classes
• shown as the stereotype metaclass of Class

32

• Importing a package
• the contents of the target packages (and its
  sub-packages) may be referenced by the client
  package
• does not modify the namespace of the client
• the visibilities are combined according to the
  rule that the most restrictive visibility in the
  set is obtained
• represented by imports dependency relation
• Example

33

• Object
• represents a particular instance of a class
• has identity and attribute values
• Example

34

• Binary Association
• is an association among exactly two classes
  (including a reflexive association)
• predefined constraints, e.g. or
• Notation
• consists of
• association ends (2), name, association class
  (optional)
• Example

35

• Association end
• an end of an association where it connects to a
  class
• each association has two or more ends
• Notation
• kinds of adornments of an association end
• multiplicity
• ordering
• the set of related elements can be
  ordered,unordered
• qualifier
• navigability
• aggregation (a diamond)
• rolename
• indicates the role played by the class
• changeability of the links, e.g. frozen or
  addOnly
• visibility

36

• Aggregation and composition
• aggregation (a diamond)
• a whole-part relationship
• also treated as an ownership by reference
• composition (a filled-diamond
• aggregation with strong ownership and coincident
  lifetime as part of the whole
• parts
• may be created after the composite itself
• they live and die within the whole
• can be explicitly removed before the death of
  the whole
• the multiplicity of the aggregate end may not
  exceed one (it is unshared)
• also treated as an ownership by value

37

• Example (of an aggregation and composition)

38

• Multiplicity
• specifies the range of allowable cardinalities
  that a set may assume
• a comma-separated sequence of integer intervals
• lower-bound .. upper-bound, a number, - many
• Qualifier
• an attribute or list of attributes whose values
  serve to partition the set of objects associated
  with an object across an association
• multiplicity
• 0..1 - a unique value may be selected, but
  every possible qualifier value does not
  necessarily select a value
• 1 - every possible qualifier value selects a
  unique target
• - the qualifier value is an index that
  partitions the target objects into subsets

39

• Example (of a qualifier)

40

• Association class
• an association that also has class properties
• it is a single model element (association
  linked class)
• Example

41

• N-ary association
• an association among 3 or more classes
• may not contain the aggregation marker
• Example
• This example shows the record of a team in each
  season with a particular goalkeeper.The
  goalkeeper might be traded during the season and
  can therefore appear with different teams.

42

• Generalization
• taxonomic relationship between a more general
  element and a more specific element that is fully
  consistent with the first element and that adds
  additional information.
• Notation
• discriminator
• the name of a partition of the subtypes of the
  superclass.
• constraints
• overlapping - inheritence from more subclasses
  allowed
• disjoint - inheritence from more subclasses NOT
  allowed
• complete - all subclasses have been specified
• incomplete - there are additional subclasses
  that are not yet in the model

43

• Example (of a generalization)

44

• Dependency
• indicates a semantic relationship between two (or
  more) model elements
• predefined kinds
• trace - connects the same concept at different
  levels of meaning (history)
• refine
• uses - operation calling, instantiating, etc.
• bind - binding of template parameters to actual
  values
• Example

45

• Derived element
• is one that can be computed from another one
• is shown for clarity or for design purposes
• adds no semantic information
• Example

46

• Process of static structure modelling
• Identify classes
• from Glossary
• from Business Model
• stored information items
• from use case realizations
• Specify the semantics of classes
• responsibility
• attributes, operations and interfaces
• Identify relationships among classes
• domain based associations
• object interactions
• generalization and aggregation relationships
• Structure the model into packages

47
Interaction diagrams

• Sequence siagrams
• Collaboration diagram
• show a pattern of interaction among objects
• they express similar information but show it in
  different ways
• Multiobject
• Message flow

48

• Sequence siagrams
• show an interaction arranged in time sequence
• show the sequence of messages exchanged among
  objects
• for real-time specifications and complex
  scenarios
• Collaboration diagram
• represents a Collaboration and an Interaction
• Collaboration
• a set of objects related in a particular context
• context is a collaboration diagram without
  messages
• Interaction
• a set of messages exchanged among the objects
  within a collaboration to effect a desired
  operation or result.
• shows an interaction organized around the objects
• does not show time as a separate dimension
• may be attached to an operation or a use case

49

• Example (of a scenario diagram)

50

• Example (of a collaboration diagram)

51

• Multiobject
• represents a set of objects
• used to show operations that address the entire
  set, rather than a single object in it
• Example

52

• Message flow
• the sending of a message from one object to
  another
• shown as a labeled arrow placed near a link
• kinds of messages (control flow type)
• procedure call, asynchronous, synchronous
• balking, time-out, ...
• Notation
• predecessor guard sequence-expression iteration
  return-value message-name argument-ist
• predecessor - list of sequence numbers
• the message flow is not enabled until all of the
  listed messages have occured
• represents a synchronization of threads
• gurad - condition clause
• iteration - iteration clause

53

• Example (of message flows)
• 2 display (x, y) simple message
• 1.3.1 p find(specs) nested call with return
  value
• x lt 0 4 invert (x, color) conditional message
• A3,B4/ C3.1 update () synchronization,iteration
  

54

• Process of interaction modeling
• Identify objects participating in the
  collaboration
• Trace an interaction (scenario or algorithm) and
  add messages and links
• Specify synchronization (if needed)

55
Statechart diagrams

• State
• Composite states
• Event
• Simple and complex transitions
• History

56

• Statechart diagram
• shows the sequences of states that an object goes
  through during its life in response to received
  stimuli
• a state machine is attached to a class or a
  method
• Example

57

• State
• a condition during the life of an object during
  which performs some action, or waits for some
  event
• Notation
• name
• internal transitions
• activities performed in response to events
  received while the object is in the state,
  without changing state
• event-name argument-list condition / action
• special (predefined) events
• entry / action action performed on entry to the
  state
• exit / action action performed on exit from the
  state
• do / action action performed during the state
• action
• action name
• target.event(arguments)

58

• Example (of states)

59

• Composite states
• a state can be decomposed using (one of these)
• and-relationships into concurrent substates
• or-relationships into mutually exclusive disjoint
  substates

60

• Example (of composite states)

61

• Event
• an occurrence that may trigger a state transition
• kinds of events
• ChangeEvent -occurs whenever the value of the
  expression changes from false to true
• SignalEvent - receipt of an explicit signal
• CallEvent - receipt of a call for an operation
• TimeEvent - passage of a designated period of
  time
• Notation
• event-name ( parameter-list)
• Example
• when (balance lt 0)
• after (5 seconds)

62

• Simple transition
• a relationship between two states indicating that
  an object in the first state will enter the
  second state and perform certain specified
  actions when a specified event occurs if
  specified conditions are satisfied
• the trigger for a transition is the occurrence of
  the event labeling the transition
• Notation
• even( parameters) condition / action
  target.event(parameters)
• Example
• right-mouse-down (location) location in window
  / object pick-object (location)
  object.highlight ()

63

• Complex transition
• may have multiple source states and target states
• represents a synchronization and/or a splitting
  of control into concurrent threads without
  concurrent substates
• is enabled when all of the source states are
  occupied
• fires all of its destination states are occupied
• Example

64

• History
• a state region may contain a history state
  indicator
• may have any number of incoming transitions
• may have at most one outgoing unlabeled
  transition (default previous state)
• transition to the history indicator indicates
  that the object resumes the state it last had
  within the complex region
• kinds of history indicator
• shallow history
• object resumes the state it last had at the same
  level as the history indicator
• deep history (indicated by H)
• object resumes the state it last had at any depth

65

• Example (of a history)

66

• Process of statechart modeling
• Identify states
• Identify external events which can cause change
  of status
• To each state attach transitions based on events
• Add transition and internal actions
• Identify AND/OR substates

67
Activity diagrams

• Action state
• Decision and Merge
• Swimlanes
• Object flow relationship
• Controll icons

68

• Activity diagram
• a variation of a state machine in which the
  states are Activities representing the
  performance of operations and the transitions are
  triggered by the completion of the operations
• is attached to a class or to the implementation
  of an operation or a use case
• the purpose is to focus on flows driven by
  internal processing (as opposed to external
  events)
• use activity diagrams in situations where all of
  the events represent the completion of
  internally-generated actions (that is, procedural
  flow of control)
• use ordinary state diagrams in situations where
  asynchronous events occur

69

• Example (of an activity diagram)

70

• Action state
• a state with an internal action and at least one
  outgoing transition representing the completion
  of the action
• should not have internal transitions or outgoing
  transitions based on explicit events
• the normal use is to model a step of an algorithm
• Action
• represented by an action-expression
• may use only attributes and links of the owning
  object

71

• Decision and Merge
• Decision
• branching of transitions based on boolean
  conditions
• may have a predefined guard "else"
• transitions from the decision may not have an
  event trigger
• Merge
• used to merge decision branches back together
• Example

72

• Swimlanes
• actions may be organized into swimlanes
• kind of package for organizing responsibility for
  activities within a class
• often correspond to organizational units in a
  business model
• Object flow relationship
• objects that are input to or output by an action
  may be shown as object symbols
• the control flow (solid) arrows is omitted when
  the object flow (dashed) arrows is specified
• frequently the same object is manipulated by a
  number of successive activities
• to distinguish its various appearances, the state
  of the object may be supplied (in )

73

• Example (of swimlanes and object flow)

74

• Controll icons
• provide explicit symbols for certain kinds of
  information that can be specified on transitions
• are not necessary for constructing activity
  diagrams
• Signal receipt
• a dashed arrow may be drawn from the sender
• Signal sending
• A dashed arrow may be drawn from to the receiver
• Deffered event
• an event that occurs must be deferred for later
  use (durig some activity normally an event that
  is not handled immediately is lost.)
• each state or activity specifies a set of events
  that are deferred
• is shown within the state followed by / defer

75

• Example (of control icons)

76
Implementation diagrams

• Component diagram
• Component
• Deployment diagram
• Processor
• Device
• Connection

77

• Component diagram
• shows the dependencies among software components,
  including source code components, binary code
  components, and executable components.
• Component
• represents a distributable piece of
  implementation of a system, including software
  code (source, binary, or executable) but also
  including business documents, etc., in a human
  system.
• Stereotypes
• ltltdocumentgtgt
• ltltexecutablegtgt
• ltltfilegtgt
• ltltlibrarygtgt
• ltlttablegtgt

78

• Example (of component diagram)

79

• Deployment diagram
• shows the configuration of run-time processing
  elements and the software components, processes,
  and objects that live on them
• Processor
• a piece of HW capable to execute programs
• may show a list of processes
• Device
• a piece of HW incapable of executing programs
• Connection
• HW (physical) connection between two nodes
• the type of communication can be specified by a
  stereotype, e.g. ltltTCP/IPgtgt

80

• Example (of a deployment diagram)

81

• Links
• www.rational.com
• www.omg.org

82

• Stereotypes
• prevent explosion of modeling elements in UML
• adding of semantically new elements, whithout
  changing the language
• apply to model elements, not to instances
• extensions to modeling language, not runtime
  environment

83

• Stereotypable Elements
• Static/Structure
• Association (implicit,local, global,)
• Generalization (implementation)
• Dependency, Usage (call, create, send,
  instantiate), Abstraction (derive, realize,
  refine)
• Class (type, interface, utility ), Attribute
• Component (document, file, exe, library,)
• Behavior
• Method/Operation (create, destroy)
• Collaborations, Flow, Interaction
• Use cases
• States (activity)
• Supplementary
• Comment
• Constraint

84
(No Transcript)
85
(No Transcript)
86
(No Transcript)
87
(No Transcript)
88
Business Modeling Extension
89
Soft. Development Processes Extension