Safety-I

Safety-II

Features of the approach

Analytic approach

Synthetic approach

Definition of safety

The number of failures is small enough to be demanded

The number of successes is as high as possible

Purpose and type of safety management

· Prevent things from going wrong

· Make things work well under fluctuations and constraints

· Reactive safety management

· Advanced safety management

Target of learning

Learn from failure cases

Learn from daily practice

How to understand the system to handle

· Static system without change (static system)

· Dynamic system that keeps changing from moment to moment (dynamic system)

· Easy-to-use system (tractable system)

· Cumbersome system (intractable system)

How to perceive failure and success

The path of failure and success is different

Failure and success happen in the same way

Relationship between process and result

Linear model (causal relationship)

Non-linear model (interaction and feedback)

Human position in safety

Humans work negatively for safety and are a risk factor

Humans are essential to the safety and flexibility of the system

How to perceive performance fluctuations

Harmful and should be removed as much as possible

Irreversible, useful, monitored and managed

Points of interest

· What (event) happened

· What (phenomenon) is occurring in the behavior of the entire system

· Why it happened

· How it happens (interaction)