UML

1
UML

• By Adwait Moghe
• CPSC 606 Presentation

2
Overview

• Introduction
• History
• Goals
• Diagrams and Examples
• Latest Changes
• Disadvantages
• Conclusion

3
What is UML?

• Unified Modeling Language (UML) is a standard
  language for specifying, visualizing,
  constructing software artifacts.
• Not necessarily restricted to software systems
  used in business modeling.
• Has proven successful in modeling of large and
  complex systems.
• Uses graphical notations to describe the
  architecture of software.
• We have used UML in the diagrams for HEASSISTANT.

4
Goals

• Provide users a expressive, visual language to
  enable sharing of meaningful models.
• Enables developers to compare models before
  implementation phase.
• Independent of programming language and
  development process.
• Encourage growth of Object Oriented Tools market.

5
History

• First modeling languages 1970s.
• More than 50 modeling languages present during
  1994. Lead to method wars.
• Methods began to incorporate each others
  techniques.
• In 1994, Grady Booch and Jim Rumbaugh (Rational
  Software Corporation) unified Booch and Object
  Modeling Technique methods to create UML.
• Ivar Jacobson incorporated the OOSE method in
  1995, leading to UML version 0.9 in late 1996.

6
UML Versions

• UML 1.0 was created through a collaboration of
  various organizations Microsoft, IBM, HP, etc.
• Today, UML is on Version 2.0.
• It is managed by the Object Management Group
  not for profit consortium. UML specification is
  available for download at http//www.uml.org/
• Tools that conform the latest 2.0 specification
  Rational Software Architect, Sparx System
  Architect, StarUML, etc.

7
Types of UML Diagrams

• Types of UML diagrams (total of 13 main ones
  shown below)
• Use case diagrams
• Class diagrams
• Interaction Diagrams - Sequence and Collaboration
• State Diagrams
• Activity Diagrams
• Implementation Diagrams - Component and
  Deployment
• We have done some of these for HEASSISTANT.

8
Use Case Diagrams
Use Case diagrams describe what a system does.
HEASSISTANT simply had 1 actor, but generally, we
have multiple actors.
9
Class Diagrams
Note advanced additional features such as
abstract classes, generalization (inheritance),
aggregation (orderdetails make up order)
10
Sequence Diagrams
11
Collaboration Diagrams

• Note the use of sequence numbers
• Top level is assigned 1.1 additional dots per
  level away from the user interface.

12
State Diagrams
Lifetime of a login class.

• Show the state of a particular object
  throughout the system lifetime.
• Not necessary for all objects just the
  critical ones.
• Super states can be used to nest states to
  make diagram easier to read.

13
ACTIVITY DIAGRAMS

• A flowchart of the activity in a system.
• Elegant way to show conditional flows of
  execution.
• For use in multithreaded environments can
  show creation of parallel threads of execution,
  stopping of threads of execution.
• Usually one per use case. Objects involved are
  given their own swimlanes.
• Example on next page shows activity flow for
  "Withdraw money from a bank account through an
  ATM.
• Activities in parallel debiting account,
  removing money from slot.

14
(No Transcript)
15
COMPONENT AND DEPLOYMENT DIAGRAMS
High level component communication and
dependencies.
16
Certification

• OMG offers individual certification programs for
  UML 2.0 with 3 levels Fundamental,
  Intermediate, and Advanced.
• Price per exam is 200 dollars, but Fundamental is
  prerequisite to Intermediate.. etc.
• OMG also certifies UML compliant tools from
  vendors.
• Gives vendors right to place OMG certified
  logos on products and websites.

17
UML 2.0 Structure

• Comprised of four parts superstructure,
  Infrastructure, Object Constraint Language,
  Diagram Interchange
• Superstructure defines the UML diagrams.
  Large 710-page PDF free to download from OMG
  website.
• Infrastructure - defines the base
  classes/components used by the Superstructure.
• Object Constraint Language formal way of
  specifying constraints on objects within a
  diagram defined in the Superstructure.
• Diagram Interchange standard for exchange and
  storage/retrieval of UML diagrams for different
  software tools.

18
State of UML Today

• Size of the UML specification is growing
  tremendously.
• Changes are being made in the superstructure.
  Example timing diagrams added but werent
  present in previous versions.
• Extensions to UML being written to handle other
  technologies CORBA, certain Security
  extensions.
• Requests for Proposal (RFP) are found on OMG
  websites.

19
Significant changes in 2.0

• Activity diagrams completely overhauled OMG
  realized they were being used for business
  modeling instead of class modeling. Diagrams
  were made more similar to flowcharts.
• Package Diagrams added for high level overview of
  code structure.
• Collaboration diagrams renamed as communication
  diagrams but specification remains the same.
• Timing diagrams added for real-time applications.

20
Disadvantages of UML

• Still no specification for modeling of user
  interfaces.
• Business rule specification a group exists for
  this within the OMG, so we should see something
  in UML 2.1.
• Poor for distributed systems no way to formally
  specify serialization and object persistence.
• Example no way to specify that an object
  resides on a server process and shared among
  instances of a running process.

21
Disadvantages to UML (continued)

• Requires training/certification when working with
  enterprise class systems wasted resources.
• Management forcing UML on developers.
• Semantics too imprecise leading to subjective
  interpretations while formal testing/verification
  Leads to too many diagram notes.
• Too bloated contains specifications needed very
  rarely.

22
5 Questions

• What is UML?
• How has UML changed over its versions ?
  (currently 2.0)
• Who manages UML?
• What is the best tool for creating UML diagrams?
• Is UML restricted to OOP languages due to
  features such as class diagrams?

23
Questions?

• Thank you

24
References

• http//www.uml.org/
• http//atlas.kennesaw.edu/dbraun/csis4650/AD/UML
  _tutorial/
• http//bdn.borland.com/article/0,1410,31863,00.htm
  l
• http//en.wikipedia.org/wiki/Unified_Modeling_Lang
  uage