Nelson Aalen plot

Figure 17.7 Nelson Aalen plot of accidents in a large construction project. The straight line shows the accepted development, when the safety goal is to end up at an accumulated TTTrate below 20. This corresponds to a maximum of 214 accidents.

Figure 17,7 shows a so-called Nelson Aalen plot of the accumulated number of accidents. The higher the inclination, the higher the frequency of accidents. A related SFfE performance goal is to achieve a reduced number of accidents at the end of the period. This shows up as a straight line in the plot. When the actual performance lies above this line, corrective actions need to be taken. 

Nelson Aalen plot of accidents in a large constrnction... 

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