Tools & Methods

Risk matrices do not replace risk reasoning

A coloured cell is a communication device. Good safety decisions still depend on scenario quality, exposure, uncertainty and control effectiveness.

Risk matrices are useful because they force teams to discuss severity and likelihood. They become dangerous when the score is mistaken for the analysis.

Questions behind the cell

  • What exact scenario is being assessed?
  • Which population, fleet or operating exposure is relevant?
  • What evidence supports the likelihood estimate?
  • How independent and effective are the controls?
  • What uncertainty remains?

The matrix should summarise a documented reasoning chain, not substitute for it.