Safety Analysis and Design
What is Safety?
Safety is freedom from accidents or losses.
Normally concerned with human or animal death or injury
May be applied to any system in which you desire to avoid certain outcomes
Safety is not reliability!
Reliability is the probability that a system will perform its intended function satisfactorily.
Reliability is a stochastic measure system function delivery
Safety is not security!
Security is protection or defense against attack, interference, or espionage.
Note: the German word sicherheit relates to both security and safety, but we draw a distinction in English
Dependability is the term used for the integration of Safety, Reliability, and Security
Resilience is the term for the ability of a system to provide service under different, often unexpected, circumstances. It includes Dependability and Adaptability.
Example Fault Tree Analysis
with the UML Dependability Profile (see bottom of page)
The UML Dependability Profile
This Rhapsody profile supports safety, reliability, and security analysis.