Control the Risk level

The Basic idea behind a Risk based Safety Management System is to control the risk level.

In the "Old-Days"-graph, shown below, the Safety Department in an organization implements a procedure or technical solution every time an accidents occur: "Oops, we did it again". Time goes on and evidently, a major accident occurs one day.

In the "Now-a-days"-graph, all accidents have been foreseen in the hazard-log and mitigation actions have therefore been implemented by the Safety Department before the accidents occur.






Interpretation

What happens if the risk management level (on the graph) is set too low?

Then - of course - we will experience more small event and accidents.

What happens if the risk level is set too high?

Then we will will not experience any events and accidents. But safety is expensive, this means an organization with a too high risk management level will have higher operational costs.

Lets say we have two Railway Operators, called A and B, and lets say that they are competing of operating a train fleet somewhere in Europe. Operator A has implemented a too high risk management level compared to Operator B and compared to the guidelines set out by the local Safety Authority. In this case Operator B has lower expenses on Safety and will therefore be able to make a better offer.

Next chapter >> 1.3 How to measure "Risk"

Focus on the Source (/EN 50126/)

2.2.2 Focus on the source (EN 50126:1999)

The concept of risk based safety management is explained in chapter 4, “Railway RAMS”.

In chapter 4 is stated that the risk evaluation shall be performed:

”4.6.1 Risk concept:

The concept of risk is the combination of two elements:
the probability of occurrence of an event or combination of events leading to a hazard, or
- the frequency of such occurrences;
- the consequence of the hazard.

4.6.3.2 Risk evaluation shall be performed by combining the frequency of occurrence of a hazardous event with the severity of its consequence to establish the level of risk generated by the hazardous event.

4.6.3.3 Risk acceptance should be based on a generally accepted principle.” (e.g. the ALARP principle).

The main hazards and the acceptable risk level shall be defined in phase 1, ”Concept”.

“6.1.3.4 Requirement 4 of this phase shall be to obtain information about:
- previous RAMS requirements and past RAMS performance of similar and/or related systems.
- identified sources of hazards to RAMS performance.
- current Railway Authority Safety Policy and Targets.
- safety legislation.”