safety and reliability engineering part 1: introduction€¦ · · 2009-05-05safety and...

Safety and Reliability EngineeringPart 1: Introduction

Prof. Dr.-Ing. Stefan Kowalewski

Chair “Informatik 11”, Embedded Software LaboratoryRWTH Aachen University

Summer term 2006

Organisational issues /2

Website:

www-i11.informatik.rwth-aachen.de,Lehre / Sommersemester 2006,Safety and Reliability Engineering

- Announcements

- Slides

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Safety and Reliability EngineeringPart 1: Introduction, Slide 2

© Stefan Kowalewski, 21 April 2005

Organisational issues

Right lecture for you?

- Diplom Informatik / Praktische Informatik

- Diplom Informatik / Vertiefungsgebiet Software für eingebettete Systeme

- MSc Software Systems Engineering

- MSc Software Systems Engineering / Specialization AreaEmbedded Systems

- MSc Media Informatics

- ERASMUS




Dates:

- Lecture Wednesday, 10:00-11:30, AH III

- Exercises Thursday, 13:30 – 15:00, AH III, Start: 20.04.06

Exercises:

- Depending on number of participants either one or two groups

- List will be circulated right now.

Video recording of last year‘s lecture:

www-i11.informatik.rwth-aachen.de,Lehre / Sommersemester 2005,Safety and Reliability Engineering




No lectures:- 7 June 2006 (Excursion week)

- 14 June 2006 (Dies)

Dates and places for written examination (no oral exams):

- MSc Software Systems Engineering (4 ECTS) &Übungsschein Diplom Informatik:

Wednesday, 12 July 2006, 10:00 – 11:30, Room AH III



Tutor:

Contact: [email protected]: Room 2319, RWTH Aachen


Andreas Polzer



Lecturer

Prof. Dr. Stefan Kowalewski

- 1990 Diplom degree in electrical engineering from theUniversity of Karlsruhe

- 1995 PhD, Department of Chemical Engineering,University of Dortmund

- 2000 – 2003Head of research group (foundations ofsoftware technology) at Corporate Research andAdvanced Engineering at Robert Bosch GmbH,Frankfurt am Main

- 2003 Habilitation in Control and Safety Engineering, University of Dortmund

- Since 11/2003Professor for Embedded Software, RWTH



By colleagues:Prof. Mantel (i4) Formal Methods for Information Security

This semester by i11:Embedded Software Engineering, Tuesday, 10:00, AH IIFormale Methoden für eingebettete Systeme (in German), Thursday, 10:00, AH I

Winter term:Introduction to Embedded SystemsDynamic Systems for Computer Scientists

Possible additions for specialization area:Prof. Lichter: SW Quality Assurance and Project MangementProf. Abel (FB 4): Rapid Control Prototyping (in German)

Related lectures



Literature

The lecture will not be following one single book.Books which cover aspects of the lecture (but also much more) are forexample:- N. Storey: Safety-critical computer systems. Prentice Hall, 1996.- N. Leveson: Safeware. Addison-Wesley, 2001.- J. Barnes: High integrity software. Addison-Wesley, 2003.- K. Simpson, D. Smith: Functional Safety. Elsevier, 2004.- A. Birolini: Reliability Engineering. Springer, 2004.- S. Montenegro: Sichere und fehlertolerante Steuerungen. Hanser,

1999.More to be added on website.

Interesting link:- http://catless.ncl.ac.uk/Risks



Lecture Contents

Analysis and design methods for achieving safety and reliability of software-intensive embedded systems



Agenda:Introduction (this lecture)(organisational issues, context, motivation) Terminology (next lecture)Reliability/Availability(measurement, modeling, analysis, prediction,design principles)Safety(requirements, assessment, analysis techniques, design for safety, safety lifecycle, IEC 61508)

Lecture Contents




⇒What is an embedded system?Precise meaning of safety and reliability?

Lecture Contents




What is an embedded system?

User EnvironmentPeopleEmbedded

System

Embedding System

Embedded System =

A computer system which is integrated into another system, theembedding system. The requirements for the embedded systemmust be derived from the requirements for the embedding system.

Examples?



Examples of embedding systems



Differences to “desktop“ computing?

Interaction with physical environmentClosed loopNo or very restricted human/computer interfaceNo or very restricted maintenance possibilitiesPart of competitively priced products (high volumes)Tight resource constraintsOften special hardwarePart of engineering productHigh product generation frequencyOften many variants Malfunction may lead to damage



Current situation in the embedded systems industries

Increasing propagation of embedded systems into most economical areasIncreasing integration and networking of systemsIncreasing complexityShorter development cyclesIncreasing resource constraintsIncreasing importance of software compared to hardware

⇒Traditional industries (automotive, rail, aerospace, appliances, health care …) have not been prepared for this paradigm shift.

⇒ Increasing quality problems.



Examples (1)

DETROIT April 2, 2004 . GM will recall 12,329 Cadillac SRXsequipped with all-wheel drive, including 11,375 in the United States, following two reports of a one-second delay in theanti-lock brakes activating to stop the vehicle, spokesmanJim Schell said.The problem, due to a software anomaly, only occurs duringthe first few seconds of driving when the SUV is movingslowly, he said. One owner crashed his SRX into his garagewall following the brake delay, but was uninjured.

Source: www.theautochannel.com/news/2004/04/02/187644.html



Examples (2)



Examples (3)



Examples (4)Safety and Reliability Engineering

Part 1: Introduction, Slide 2021 April 2005

Quelle: HALLO –Das Magazin,Ausgabe 09/03

www.hallo-das-magazin.de

Examples (5)

Frequent delays of SOP (start of production) of new car modelsIncrease of software/electronics related breakdowns by 23% from 1998 to 2001.Tilting train “Pendolino“: Four years after commissioning in Germany, 11 out of 15 trains are still shut down.ICE 3 high speed train: Failures of the bord computer caused the air conditioning to shut down.Autumn 2004: Wheel glide protection failed in regional trains causing massive delays.



Examples (6)

A computer problem on the Canadian Air Transat flight caused an emergency landing in the Azores last summer. Apparently, as earlyreports describe, a "computer program" incorrectly reported a fuelleak as an "imbalance". To correct the "imbalance" the "computerprogram" diverted fuel from a good tank to the tank that was leaking thus both tanks were emptied. Inflight. The skill of the pilotand the availability of an island with an airport in the Atlantic Ocean averted a disaster.

Source: Canadian Press, *Toronto Globe and Mail*, *Toronto Star*, & other Canadian newspapersTaken from John Johnson, Risk Forum, 4 March 2002



⇒What is an embedded system?Precise meaning of safety and reliability?

Lecture Contents




Precise meaning of safety and reliability?

What is the difference between safety and reliability?Is a safe system necessarily a reliable system?Is a reliable system necessarily a safe system?



Precise meaning of safety and reliability?

What is the difference between safety and reliability?Is a safe system necessarily a reliable system?Is a reliable system necessarily a safe system?

⇒ Terminology is important!



Further terminology

English:Security (difference to safety?)Availability (difference to reliability?)Dependability (difference to reliability?)Failure, fault, error, defect, bug, malfunction, …

German:ZuverlässigkeitVerfügbarkeitVerlässlichkeitFehler, Ausfall, Versagen, Defekt, Fehlfunktion ….

⇒ Precise definitions in the next lecture



safety and reliability engineering part 1: introduction€¦ · · 2009-05-05safety and...

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