Division STEP 2: SCORING OF THE SAFETY RISK WITHIN THE ERCS MATRIX
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The safety risk score is a two-digit value where the first digit corresponds to the alphabetic value resulting from the calculation of the severity of the occurrence (severity score A to X) and the second digit represents the numerical value from the calculation of the corresponding score of the occurrence (0 to 9).
The safety risk score shall be put into the ERCS matrix.
For each given safety risk score there is also a numerical equivalent score for aggregation and analysis purposes which is explained below under ‘Numerical equivalent score’.
The ERCS matrix reflects the safety risk score and the numerical associated figures of an occurrence as follows:
In addition to the safety risk score and to facilitate the determination of the urgency of the recommended action to be taken about the occurrence, the following three colours could be used in the ERCS matrix:
| Colour | ERCS score | Meaning |
|---|---|---|
| RED | X0, X1, X2, S0, S1, S2, M0, M1, I0 | High risk. Occurrences with the highest risk. |
| YELLOW | X3, X4, S3, S4, M2, M3, I1, I2, E0, E1 | Elevated risk. Occurrences with intermediate risk |
| GREEN | X5 to X9, S5 to S9, M4 to M9, I3 to I9, E2 to E9. | Low risk occurrences |
The green area of the matrix contains lower risk values. They provide data for in-depth analysis on safety related occurrences that could, either in isolation or in conjunction with other events, increase the risk values of such occurrences.
Numerical equivalent score
Each ERCS score is assigned a corresponding numerical value of risk magnitude to facilitate the aggregation and numerical analysis of multiple occurrences with an ERCS score:
| ERCS Score | X9 | X8 | X7 | X6 | X5 | X4 | X3 | X2 | X1 | X0 |
| Corresponding numerical value | 0,001 | 0,01 | 0,1 | 1 | 10 | 100 | 1000 | 10000 | 100000 | 1000000 |
| ERCS Score | S9 | S8 | S7 | S6 | S5 | S4 | S3 | S2 | S1 | S0 |
| Corresponding numerical value | 0,0005 | 0,005 | 0,05 | 0,5 | 5 | 50 | 500 | 5000 | 50000 | 500000 |
| ERCS Score | M9 | M8 | M7 | M6 | M5 | M4 | M3 | M2 | M1 | M0 |
| Corresponding numerical value | 0,0001 | 0,001 | 0,01 | 0,1 | 1 | 10 | 100 | 1000 | 10000 | 100000 |
| ERCS Score | I9 | I8 | I7 | I6 | I5 | I4 | I3 | I2 | I1 | I0 |
| Corresponding numerical value | 0,00001 | 0,0001 | 0,001 | 0,01 | 0,1 | 1 | 10 | 100 | 1000 | 10000 |
| ERCS Score | E9 | E8 | E7 | E6 | E5 | E4 | E3 | E2 | E1 | E0 |
| Corresponding numerical value | 0,000001 | 0,00001 | 0,0001 | 0,001 | 0,01 | 0,1 | 1 | 10 | 100 | 1000 |
Both column 10 and the row A in the matrix bear the value 0 as the corresponding numerical value.