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HSE FRI calculator withdrawal

The public HSE Fatigue and Risk Index (FRI) calculator — a spreadsheet tool — was withdrawn from the HSE website in June 2021. This page explains what that does and does not mean, carefully and without speculation.

It is not legal advice, and it does not present any tool as current HSE-endorsed software.

The research and the tool are different things

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It helps to separate two things:

  • HSE RR446 — the 2006 research report describing the fatigue / risk index methodology. This is a research source.
  • The FRI calculator — a spreadsheet that implemented that methodology so users could enter rosters and read outputs. This was a tool.

The tool was withdrawn. The research report remains a public HSE research output. Distinguishing the two avoids the mistake of treating a withdrawn spreadsheet as if it were the whole body of knowledge.

Why it was withdrawn

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According to ORR guidance, HSE determined that the software platform the calculator ran on was an older version of Excel that could no longer be supported and maintained on the HSE website. HSE also noted that the tool’s design would benefit from improvement to promote better understanding of its outputs, its limitations, and its role within a fatigue risk management system — including because there had been cases of the FRI being misused to justify work patterns that clearly required further action.

ORR guidance indicates that existing users with access to the tool may continue to use it provided they have the necessary expertise and understand its outputs and limitations. This page does not host, link to, or distribute the tool.

Withdrawn tooling does not make the concepts useless

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Withdrawal of a specific spreadsheet does not mean fatigue risk index concepts are invalid. The underlying ideas — that timing, cumulative load, and workload and breaks shape fatigue exposure — remain well established and are reflected in wider guidance such as HSG256 and ORR’s rail fatigue guidance.

Equally, this does not mean all fatigue risk index use is invalid. Many organisations use biomathematical models within a governed process; the point is to use them competently and with understanding of their limits.

Why competent review matters more, not less

Section titled “Why competent review matters more, not less”

The reasons for withdrawal reinforce a theme across this site: model outputs are decision-support, not decisions.

  • Outputs are modelled estimates of relative exposure, not measures of real-time alertness or fitness for duty.
  • They should be interpreted with competent judgement, not used to rubber-stamp a demanding pattern.
  • Any thresholds are organisational policy thresholds that may vary, not legal limits — HSE does not currently specify mandatory FI values.

See limitations of fatigue models and Fatigue Index vs Risk Index.

How public pages should reference the FRI

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Because the public calculator is withdrawn, responsible referencing means:

  • Cite RR446 and current HSE and ORR guidance rather than presenting the calculator as current HSE-endorsed software
  • Avoid implying an “official current HSE fatigue tool” is available to download
  • Describe methods and concepts, and paraphrase source guidance rather than reproducing tables or formulas
  • Frame any index values as modelled, relative, and non-statutory
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References

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