An Introduction to UML

1
An Introduction to UML Modeling Resources Using
UML

• Rahul Shah
• EE249 Discussion
• Sept. 25, 2001

2
Talk Outline

• An introduction to UML
• Different views in UML
• Examples from PicoRadio UML documentation
• Discussion of Bran Selics paper, A generic
  framework for modeling resources with UML

3
The Development Process
UML
4
Unified Modeling Language

• Object oriented modeling language
• Intended to model discrete systems such as
  software, firmware or digital logic

Models are used to capture and precisely state
requirements and domain knowledge so that all
stakeholders may understand and agree on them.
(Rumbaugh, Jacobson Booch)
5
UML Views

• Structural things in the system and their
  relationship to other things
• Class diagrams
• Use case diagrams
• Component diagrams
• Dynamic system behavior over time
• Statechart diagram
• Activity diagram
• Sequence diagram
• Model management, others

6
Class Diagram
PicoRadio UML documentation
7
Use Case Diagram
PicoRadio UML documentation
8
Activity Diagram
PicoRadio UML documentation
9
Sequence Diagram
PicoRadio UML documentation
10
A Generic Framework for Modeling Resources With
UML

• Bran Selic
• IEEE Computer, June 2000.

11
Quantitative Analysis

• Schedulability analysis
• Deterministic technique
• Good for hard real-time systems
• Performance analysis
• Probabilistic characterization
• Good for soft real-time systems

12
QoS Contracts
Peer interpretation
13
UML Model of QoS Contracts
14
Management of Resources
15
Realization Mapping
Realization relationship
16
QoS Analysis

• Compare the required QoS with the offered QoS
• The offered QoS should exceed the required QoS
• Aggregated QoS characteristics can complicate the
  analysis
• Different characteristics combine in different
  ways
• Resources are often shared

17
Conclusions

• Models are useful to predict and quantify
  performance of software without actual
  construction
• Incorporating a generic QoS framework in UML
  helps us in analyzing software models
• UML is an industry standard, thus a common base
  to develop new techniques for analysis