Risk matrix

Likelihood and Consequences

If you are a supervisor responding to an incident in ERMS, you will be asked to enter the Likelihood and Consequence of the incident, in order to assign a Risk Rating. This page provides a quick reference for the meaning of each option you can choose.

Need more help or information, talk to your local Health and Safety Business Partner.

  • Consequence definitions

    Use the consequence table below to determine the severity of the incident.

    Consequences Types
    (Severity Level)    		Description
    Severe

    Severe injury/illness requiring life support, actual or potential fatality, greater than 250 days off work

    Major

    Extensive injuries requiring medical treatment (e.g. surgery), serious or permanent injury/illness, greater than 10 days off work

    Moderate

    Multiple medical treatments, non-permanent injury, less than 10 days off work

    Minor

    Single occurrence of medical treatment, minor injury, no time off work

    Insignificant

    First aid treatment, minor injury, no time off work

  • Likelihood definitions

    Use the likelihood table below to assist in determining the likelihood of the incident occurring or re-occurring.

    Likelihood
    (Probability)    		Description Probability of occurance (expected to occur)
    Almost certain Will occur in most circumstances when the activity is undertaken 90%
    Likely Will probably occurin most circumstances when the activity is undertaken 51-90%
    Possible Might occur when the activity is undertaken 21-50%
    Unlikely ould happen at some time when the activity is undertaken 1-20%
    Rare May happen only in exceptional circumstances when the activity is undertaken 1%
  • Risk rating calculation

    ERMS will automatically calculate the Risk Rating from the consequence and likelihood ratings, using the table below.

  • Risk rating priority for action

    Use the risk rating in the table below to assist in prioritising actions and associated time frames:

    Risk Rating (Priority for Action) Risk acceptance guideAction Recommended action time frame
    Extreme Not acceptable Cease or isolate source of risk Immediate
    Implement further risk controls Up to 1 month
    Monitor, review and document controls Ongoing
    High Generally (in most circumstances) not acceptable Implement risk controls if reasonably practicable 1 to 3 months
    Monitor, review and document controls Ongoing
    Medium Generally (in most circumstances) acceptable Implement risk controls if reasonably practicable 3 to 6 months
    Monitor review and document controls Ongoing
    Low Acceptable Monitor and review Ongoing