Experiences in teaching, learning and
introductory use of description
techniques
Richard Sanders
NTNU Dept of Telematics and
SINTEF Telecom and Informatics, Norway
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
1 - 31.05.2016
Background
 Description languages taught by Rolv Bræk at university
level since the 1980s
 My own lecturing at university level the last 3 years
 Holding courses for academics and industry for many
years
 Experience in using the languages since 1985
 Use of languages in development methodologies
(TIMe - The Integrated Method: www.sintef.no/time)
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
2 - 31.05.2016
Learning objectives
 Seeing the power of abstraction
 Understanding concepts: state machines, parallelism,
synchronisation and asynchronous messages
 Learning the art of system design of real-time systems
 Knowing how to analyse designs
 Managing to turn designs into working systems
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
3 - 31.05.2016
Techniques taught and used
 System modelling with emphasis on logical behaviour
 Languages for system modelling:
 UML, MSC, SDL, ASN.1, TTCN, Process Algebra
 Methods for system modelling
 Methodology for systems engineering
 TIMe, Verification and validation
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
4 - 31.05.2016
TIMe at a glance
Problem
domain
problems, ideas
Unified Modeling Language (UML)
Specification
problem
domain
product
family
UML
product needs
Application design
Framework design
Architecture design
UML
Implementation
instance needs
Market
needs
needs
needs
C++, Java, ...
Instance
system
configuration instance
needs
System
satisfied needs
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
5 - 31.05.2016
What parts of the languages
University courses:
 UML: Focus on object modelling
 MSC: Interaction models
 SDL: Basic SDL, “OO-SDL”, a selected coverage
 ASN.1: A brief intro
 Process Algebra: Introduction (more at Ph.D. level)
 TTCN: Testing principles and language
Industry courses:
 UML, MSC and SDL - a selected coverage
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
6 - 31.05.2016
Use of tools
University courses:
 Students perform compulsory assignments in groups
 Telelogic TAU for UML, SDL and MSC work
 Design
 Simulation
 Simple validation (MSC against SDL)
 Implementation platforms
 JavaFrame from Ericsson Norway: a thread-safe Java environment
for FSMs
 No tools for TTCN
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
7 - 31.05.2016
Experiences
 The languages and tools help to reach the learning goals
 Students understand parallelism!
 The languages are good for modelling and analysis
 An understandable transition to implementation is possible
 The different languages “sort of” fit together
 Good tool support
 Limited availability of adequate teaching material (books)
 Courses use a selection from books and articles
 Complex and large languages (esp. UML and SDL)
 Evolving languages
 Tools linger
 Work needed to keep material up-to-date
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
8 - 31.05.2016
The Future
 The selection of languages and tools is evaluated yearly
 Transition away from SDL/MSC to UML?
 Not presently
 If UML 2.0 is “good enough” (= expression, tools, books): probably!
ITU-T SG 17 Workshop “Use of Description Techniques”,
Geneva 23rd November 2002
9 - 31.05.2016