RATAD, Reliability And Timing Analysis of Distributed systems

Project no: 0005-19

Hans Hansson and Christer Norström

Mälardalen University, Computer Engineering Department, MRTC

Application, support letter 1 from ABB Automation Products AB and support letter 2 from Datex-Ohmeda

Comments by evaluators.

Support: 1 PhD student for 2 years decided 00-06-16.

Start: 2000-11-01 with Thomas Nolte as PhD student.

Reports: First-year-report

 

Industry contact

 

Mårten Larsson marten.larsson@se.datex-ohmeda.com

Datex-Ohmeda AB

Bromma

Project 1: TATOO Test And Testability Of Distributed Real-time Systems

Project 2: RATAD, Reliability And Timing Analysis of Distributed systems

 

Krister Hagman, krister.hagman@se.abb.com

ABB Automation Products AB

Västerås

Project: RATAD, Reliability And Timing Analysis of Distributed systems

 

Overview

Modelling and analysis are important tools in the development of safety critical real-time systems. The introduction of state-of-the-art analysis techniques in industry is however rather slow. One reason for this is the pessimism in models and analysis, e.g., schedulability analysis for realistic systems are typically based on simplifying assumptions which leads to pessimism that forces designers to make costly overdesigns, dimensioning the system for worst-case situations that may never occur. At the same time, the over all system requirement is to satisfy a reliability measure of, say, at most 10^-9 faults per hour.

This project proposes a reliability analysis method that considers the effects of faults and timing parameter distributions (including execution time distributions, jitter distributions, and sporadic task inter-arrival time distributions) on schedulability analysis. The goal is to provide designers with well founded support that allow them to make trade-offs between timing guarantees and reliability, i.e. by allowing occasional deadline misses a less costly implementation may be used, while still satisfying the over all reliability requirement.

Results

Co-operation

Publications

1. Nolte, T., Reducing Pessimism and Increasing Flexibility in the Controller Area Network. Licenciate thesis, Mälardalen University May 12, 2003.