All About Hira (Hazard Identification and Risk Assessment)
1. Risk Assessment Formula
Risk assessment formula used in HIRA ( Hazard Identification and Risk Assessment). This formula required to calculate the risk of activity which used in finding risk level by using Risk Matrix.
Risk Level :
| Level | Refer | Color |
| Low | L | Green |
| Moderate/Medium | M | Yellow |
| High | H | Red/Orange |
| Extreme | E | Red |
What is risk Matrix ?
As the name suggest risk matrix it is nothing but visual tool or chart to find the risk level of activity.
Risk matrix comes in 2 format first is 3×3 and second is 5×5.
- 3×3 matrix is basic format of risk matrix which categorizes risks based on probability or likelihood and consequence or impact. In likelihood and consequence show in low, medium and high.
- 5×5 matrix is advance format which categorizes risk more specific which you can understand in probability or likelihood it show more detail version such as rare, unlikely, moderate , likely and almost certain and in consequence or impact or severity it show negligible, minor ,moderate ,major and catastrophic.
Risk Matrix
| PROBABILITY | SEVERITY → | ||||
|---|---|---|---|---|---|
| 1 Negligible |
2 Slightly |
3 Moderate |
4 High |
5 Very High |
|
| Very Likely – 5 | 4 | 10 | 15 | 20 | 25 |
| Likely – 4 | 4 | 8 | 12 | 16 | 20 |
| Possible – 3 | 3 | 6 | 9 | 12 | 15 |
| Unlikely – 2 | 2 | 4 | 6 | 8 | 10 |
| Very Unlikely – 1 | 1 | 2 | 3 | 4 | 5 |
Risk Levels and Conditions
| Risk | Risk Level | Condition |
|---|---|---|
| 1 to 6 | Low Risk | May be acceptable but review task to see if risk can be reduced further. |
| 8 to 12 | Medium Risk | Task should only be executed with appropriate management authorization after consulting with specialist personnel. |
| 15 to 25 | High Risk | Task must not proceed, until adequate action is taken to minimize the risk. |
I hope you have understood now what is risk rating and risk matrix now we go for how to calculate risk.
Risk Assessment formula
Now this formula show how to calculate risk assessment and which you can use in your hira.
The formula of Risk Assessment is
Risk = likelihood X Severity
- Likelihood: Probability of the Hazard occuring.
- Severity: Consequence or impact of the hazard.
Example
first step is Identify the hazard:
A worker cutting metal strip with grinder machine and this grinding machine dont have machine guard
Hazard: Injury or fatality can occur due to contact with moving parts of machinery or breaking of grinding wheels can be fatal to the worker
source of Hazard: Lack of machine guarding.
Second step is Analyze Risks:
what are the chance or probability or likelihood of occuring of accident.
- Rate on 1-5 scale (1- very unlikely, 5= very likely)
- Assume Chance of occurring is 4 (likely)
what are the consequence or severity of accident.
- Rate on 1-5 (1 = Negligible, 5= very high)
- Assume severity is 5 ( very high)
Third step is calculating risk:
Use this Formula : Risk =Likelihood(L)x Severity (S)
Risk= 4×5
Risk = 20
Fourth Step is Evaluate Risk:
now use risk matrix table and find 20 number in the table which is cover in red color, now you will find risk level in risk matrix after looking in table you will find 20 comes in High risk Level.
| 15 to 25 | High Risk | Task must not proceed, until adequate action is taken to minimize the risk. |
