international railway safety conference, september 28 th 2009slide 1 railway safety and security –...
TRANSCRIPT
International Railway Safety Conference, September 28 th 2009 Slide 1
Railway Safety and Security – Two Sides of the Same Coin ? !
L. Schnieder; E. Schnieder; T. Ständer
• Introduction• The role of communication• Motivation for terminology work
• Methodical foundation• The metamodel of a linguistic sign
• Application• Formalization of the risk concept
• Formalization of the safety concept
• Formalization of the security concept
• Conclusion
Slide 3International Railway Safety Conference, September 28 th 2009
memory
mental lexicon
event schemas (scripts)
objectschemas
formulation
concept-ualization
-interpretation
transmission
mentalrepresentation
lexicalidentification
memory schemas
RECEIVER
recognition
syntactical schemas
phonetic schemas
articulationperception
sensory schemas
motor schemas
morphologicallevel
syntacticlevel
semanticlevel
pragmaticlevel
cognitivelevel
phonologicallevel
physicallevel
TRANSMITTER
IntroductionPitfalls of communication
Slide 4International Railway Safety Conference, September 28 th 2009
A formalized concept model helps to overcome lexical ambiguities!
A concept‘s designation is just the tip of the iceberg. What really matters is underneath the watersurface . . .
The meaning of a concept is often tacitly assumed:
intension extension relations
IntroductionThe importance of semantics
Slide 5International Railway Safety Conference, September 28 th 2009
semantic vagueness: terminological definitions are imprecise What characteristics describe the severity of a minor or major injury?
Duration of clinical treatment [hours] Time of convalescence [weeks] Reversibility of injury [boolean] Regain of full capacity to work [boolean]
ambiguity: different words have multiple meanings „argument“ process or result? „specification“ process or result?
inconsistency: standards are contradictory "fault" expressed by IEC 61508-4 “fault” expressed by IEC 60050(191)
October, 22nd 1895: Montparnasse train accident
General situation: language use in railway engineering is blurry there is a lack of a consistent and harmonized terminology
context dependence: standards are contradictory “signal" in communications engineering “signal” in railway engineering
IntroductionMotivation – Status quo of terminology use
Slide 6International Railway Safety Conference, September 28 th 2009
Methodical foundationMetamodel of a linguistic sign
linguistic sign
signifier (concept
designation)
signified(concept)
concept relations
extensionintension
linguistic variety
concept definition
1
1
1
n
1
1
mn
m n
Slide 7International Railway Safety Conference, September 28 th 2009
Methodical foundationRelations within a concept system
concept relation
pragmatic concept relation
hierarchical
Taxonymy(abstraction)
partonymy/meronymy
dynamic
antonymytemporal relation
causal relation
non-hierarchical
sequentialconcurrent
concept
comple-mentarity
Slide 8International Railway Safety Conference, September 28 th 2009
ApplicationRisk as a concept system
Damage
distribution of extent of damage
E(D) = MED(P(D))
distribution of frequency of occurence
E(T) = MED(P(T))
Risk
E(R) = E(D) x E(T)
11 1…* 1…*
environmental harm human harm
major injury fatalityminor injury
commercial harm / financial detriment
Slide 9International Railway Safety Conference, September 28 th 2009
ApplicationRisk as a concept system
initial risk
residualrisk
tolerable risk
necessaryrisk reduction
achievedrisk reduction
Slide 10International Railway Safety Conference, September 28 th 2009
ApplicationFormalization of the safety terminology of ISO/IEC Guide 51
char
acte
rist
ic(p
etrin
et)
pro
per
ty(U
ML
clas
s di
agra
m)
qu
anti
ty(U
ML
clas
s di
agra
m)
unimpaired assets
Harmful event(3.13)
harm(3.1)
hazard(3.3)
hazardous events(3.12)
potential hazard
risk (3.2)
haza
rdou
s
situa
tion
probability distribution function for loss frequency
probability distribution function
for loss severity
risk
probability distribution of
hazardous events
hazard rate
Slide 11International Railway Safety Conference, September 28 th 2009
ApplicationFormalization of the security terminology of the ISO/IEC Draft Guide
char
acte
rist
ic(p
etrin
et)
pro
per
ty(U
ML
clas
s di
agra
m)
qu
anti
ty(U
ML
clas
s di
agra
m)
probability distribution function for loss frequency
probability distribution function
for loss severity
risk
unwanted incident (emergency?)
harm (2.7)disaster (2.3)
threatening event(attack)
potential threat
risk
probability distribution of
threatening events
probability of threatining event
threat
unimpaired assets
thre
aten
ing
situa
tion
system boundary
Slide 12International Railway Safety Conference, September 28 th 2009
ApplicationIterative process of risk assessment and risk reduction (risk control)
system definition
hazard identification
risk estimation
risk evaluation
protective measures in design phase
protective measures in
operation phase
tolerable risk
intended use
identified hazards
initialrisk
actual risk
reduction
necessary risk reduction
risk reduction
risk analysis
risk treatment
risk assessment
residualrisk
unimpaired asset
(exposure profile)
Slide 14International Railway Safety Conference, September 28 th 2009
Tack för uppmärksamheten!
Thank you for your attention!