What is a Scenario Analysis?
A Scenario Analysis is a tool used to identify possible risks. Usually, this tool is used in succession of a brainstorm where all possible risks are identified. After the most relevant or most commonly known risks are identified a Scenario Analysis will be performed. A Scenario Analysis is then followed by or used in combination with a risk matrix so that the identified and analysed risk can be “rated” according to whatever the organization defines as their impact and likelihood descriptors.
How to use it
There is no definitive way to use this tool. You can think of your own way to use it or you can follow some general practices which are as follows:
-- Define the Threat.
-- When does the treat occur?
-- What are the meteorological conditions when the threat occurs?
-- What is the object of the threat (worker(s), tool(s), heavy equipment, etc...).
-- Describe the situation in as much detail as possible.
-- Then make an educated guess as to what the likelihood and consequence/impact of this scenario is.
An example of a Scenario Analysis is given here:
In this scenario an ammonia container is leaking due to poor maintenance and the immediate threat is to employees in the facility and people in homes around the facility.
| Scenario: | Ammonia container leaks ammonia. |
| Time of day: | Time: 09.47, Thursday October 10. |
| Meteorological conditions: | Wind blowing 3m/sec from SSW |
| Object of threat: | People/workers in nearby facilities or homes |
| Situation: | Due to poor maintenance the ammonia container has a broken or bad valve and is therefore leaking. Liquified Ammonia exits the container at 60 litres every minute or 1 litre a second (Imperial Units: 16 gallons a minute). Employees are instructed to leave the area or use PPE such as masks and chemical suits. The emergency services are to be contacted so they can come in and close the leak and clean up. |
| Scenario analysis: | |
| Likelihood and Consequence | Likelihood: Given the nature of the company, rules from the government and safe workplace instalments, this scenario is rated as unlikely. Consequence: Is high given the chemical properties of ammonia, which is very dangerous to breath. Ammonia evaporates at –33 degrees Celsius and is deadly at concentration of 5000ppm in air. |
All these factors are, of course, dependent on your organizations main area of operations. The level of detail in these Scenarios are essential to a great threat/risk mitigation. The more you know about the operation procedures the greater detail you can describe the scenario in, and then it is easier to define the risk and threats and therefore to mitigate them in some way.
With the example as it is right now, there are no definitions or descriptions of what unlikely is or what high consequence is. This is usually where risk matrix would be implemented, at the end of the first scenario analysis, where no mitigation measures have been implemented yet.
Sources
- The Danish Emergency Management Agency has a great explanation of this method in their publication (Danish only): Håndbogen for risikobaseret dimensionering.
- We are working on an international source...
