What is a bow-tie diagram and what does it illustrate?

• A. A bow-tie diagram shows the relationship between hazards, causes (threats), top events, consequences, and the barriers that prevent or mitigate those events.
• B. A bow-tie diagram maps the organizational chart of safety responsibilities.
• C. A bow-tie diagram shows chemical composition.
• D. A bow-tie diagram forecasts weather-related hazards.

Answer: (A)

A bow-tie diagram is a risk visualization that links a hazard to its potential causes (threats) and to its possible consequences, with protective barriers placed on both sides of a central top event. On the left, it shows how threats could lead to the top event and the safeguards that prevent it from occurring. On the right, it shows what could happen once the top event occurs and the barriers that mitigate or limit the resulting consequences. This layout helps clarify where controls exist, how they might fail, and where residual risk remains, making it easier to communicate risk and identify improvement points. It’s not an organizational chart, not a map of chemical composition, and not a weather forecast.