Two courses on VDM for Embedded Systems: Learning by Doing

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Two courses on VDM for Embedded Systems
Learning by Doing

• Professor Peter Gorm Larsen
• Engineering College of Aarhus
• Computer Technology Embedded Systems
• (pgl_at_iha.dk)

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Background of Students

• Students at MSc level but with an BSc in
  Engineering of embedded systems as background
• Practically oriented
• Limited introduction of proof and abstraction
• Course is meant to provide them skills for
  precision and abstraction

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Vienna Development Method

• Invented at IBMs labs in Vienna in the 70s
• VDM-SL and VDM
• ISO Standardisation of VDM-SL
• VDM is an object-oriented extension
• Model-oriented specification
• Simple, abstract data types
• Invariants to restrict membership
• Functional specification
• Referentially transparent functions
• Operations with side effects on state variables
• Implicit specification (pre/post)
• Explicit specification (functional or imperative)

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Teaching Material

• John Fitzgerald, Peter Gorm Larsen, Paul
  Mukherjee, Nico Plat and Marcel Verhoef
  Validated Designs for Object-oriented Systems.
  Springer Verlag, 2005.
• Development Guidelines for Real-Time Systems
  Using VDMTools, CSK public document 2006
• Tool used during the course http//www.vdmbook.com
  /tools.php
• Rational Rose for UML models

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Course Delivery

• Contact with the teacher
• Tuesdays 1430 1545 (I present theory)
• Thursdays 1300 1545 (students present their
  projects)
• Students read in advance of each lecture
• Combination of
• Strategy for lessons quick intro to concepts and
  then usage in larger examples
• Projects where theory is turned into practice
• Using VDMTools for projects
• Exam form
• 15 minutes oral examination without preparation
  5 minutes for evaluation
• Oral examination will be centered around projects
  performed
• Projects will be reused and extended further in
  the second course

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Structure of the first course

1. Introduction and development process
2. VDMTools and logic
3. Defining data and functionality
4. Modeling using unordered collections
5. Modeling using ordered collections
6. Modeling relationships
7. Course evaluation and revision

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Projects selected by students

1. SAFER
2. Production Cell
3. Cash Dispenser
4. CyberRail
5. Car radio navigation system
6. Self navigating vehicle
7. Personal Medical Unit

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Milestones for Projects

• Week 2 Reading existing material about the
  project and formulating a new requirements
  definition for the project to undertake with
  focus on the purpose of the model to develop
• Week 3 Complete UML class diagram for the
  project with signatures for operations/functions
• Week 45 Model and validate functionality using
  VDM
• Week 6 Project report is handed in to the
  teacher
• Week 7 Evaluation of insight gained by using the
  model-driven approach combining VDM and UML

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Structure of the second course

1. Model Structuring and Combining Views
2. Concurrency in VDM
3. Real-time modelling in VDM (over two weeks)
4. Distributed systems in VDM
5. Model Quality
6. Course evaluation and revision

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The second course will use new VDM extensions

• Developed by Marcel Verhoef and me
• Presented at FM06 conference
• Enable VDM to describe and analyse distributed
  real time systems

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Concluding Remarks

• It has been possible to extend VDM for more
  embedded and distributed systems
• Learning by doing has been successful
• Tool support is essential
• The students have acquired new skills
• If they dont use it directly afterwards at least
  new good principles have been incorporated
• Fetch course material at http//www.vdmbook.com/te
  ach.php

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Industrially Inspired Examples

• Chemical Plant Alarm Management System
• A Robot Controller
• A Road Congestion Warning System