Risk and How to use a Risk Matrix

Summary

The video explains the concept of risk as the combination of the likelihood of exposure to a hazard and the severity of the outcome. It provides examples of assessing risk in various road crossing scenarios with bikes or trucks. A key tool introduced is the risk matrix which plots likelihood against consequence to categorize risk as low, medium or high. Risk matrices allow visualization of risk levels based on categorized measures of likelihood and consequence. Despite limitations, they offer a practical way to consistently rate risks in context.

Takeaways

• 😲 Risk can be thought of as the product of likelihood of exposure to a hazard and the consequence/severity of the outcome
• 📊 Risk matrices allow visual representation of risk using likelihood and consequence
• 🟢 Low likelihood + Low consequence = Low risk
• 🟡 High likelihood + Low consequence = Medium risk
• 🟡 Low likelihood + High consequence = Medium risk
• 🔴 High likelihood + High consequence = High risk
• 📈 Risk matrices help categorize different risk levels and make decisions
• 🤔 Risk perception can vary between people and contexts
• ❗Risk matrices have limitations like subjectivity and inconsistent interpretation
• 🟠 They are still a practical tool for risk assessment with some caveats

Q & A

What are two key components that make up risk?

The two key components that make up risk are likelihood, which is how likely someone is to be exposed to a hazard, and consequence, which is how severe the outcome will be.

How can you visualize and categorize levels of risk?

You can use a risk matrix, which is a table with likelihood on one axis and consequence on the other, to visualize and categorize levels of risk as low, medium or high.

What were the likelihood and consequence when there was an infrequent number of bicycles on the road?

When there was an infrequent number of bicycles, around one every 5 minutes, the likelihood of a crash was low and the consequence was also low. Therefore the overall risk was low.

What were the likelihood and consequence when there were trucks instead of bicycles, at the same frequency?

Even with trucks only coming by every 5 minutes, so a low likelihood of a crash, the consequence if there was a crash would be high. Therefore, the overall risk was medium.

Why wouldn't you consider crossing the road if it was a busy truck route?

If it was a busy truck route, that means trucks would be going by very frequently. So both the likelihood of getting hit and the consequences if you did would be high. This puts the overall risk level in the high category.

How might categories in a risk matrix be defined?

For likelihood, high could mean an event is expected to happen often, while low means very rarely, such as once per 100 years. For consequence, high may involve multiple deaths while low means only minor injuries.

What are some limitations of using a risk matrix?

Limitations include being subjective or open to interpretation, not accounting for different time frames, and that people may not interpret the categories consistently.

Why is risk assessment important in certain situations?

Risk assessment enables appropriate actions to be taken in situations involving potential hazards, such as with new viruses, industrial accidents, or natural disasters.

What everyday risks does the passage mention people face?

Everyday risks mentioned include those from air pollution, foodborne illness, and vehicle crashes/accidents.

What does the passage say is a simple way to figure out overall risk?

The passage states that a simple way to figure out overall risk is by using a risk matrix, which combines assessments of likelihood and consequence.