scope:

This module of NR/L2/STE/003 covers the use of the Fatigue Risk Index (FRI) calculator and interpretation of the output in relation to fatigue risk.

This module applies to anyone that has a responsibility for managing staff who may be exposed to fatigue risk and especially those that manage staff who have safety critical competencies or are required to drive as a part of their duties.

The FRI was designed primarily for comparing different shift schedules but can also be used to identify any particular shift, within a given schedule, which may be of concern.

The HSE's FRI calculator is currently used for this purpose at Network Rail. The calculator is built on research looking at the effects of shift work on fatigue levels and error rates. It also takes into account factors including travel time, workload, attention and the frequency of breaks within shift as all of these have been found to impact fatigue and the risk of error.

NOTE : Within Network Rail the preferred rostering tool has the FRI functionality built into it and delivers the requirements of this standard.

The FRI should not be used on its own to consider a roster or selection of rosters. The tool does not take into account a number of factors that may impact how appropriate a particular roster is, and these include:

a) quality and length of sleep between shifts;

b) whether rest breaks are taken as detailed within the tool's default settings;

c) personal preference (are people morning/evening/night people?);

d) ability to adjust to night working;

e) whether sufficient rest is actually obtained on rest days;

f) changes in workload on site and environmental conditions during the work activity;

g) domestic and/or personal circumstances or situations;

h) whether individuals are actually turning up well-rested and fit for duty.

These should be considered at a local level when reviewing the roster and judgement made about the impact they might have. Education on individual responsibility, health and wellbeing lifestyle choices on managing fatigue outside of work is advisable.