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Organisational policy thresholds

Organisational policy thresholds are internal trigger levels — often based on fatigue risk index (FRI) outputs — that prompt review, escalation, or documented decision-making. They are not the same as legal limits, and HSE RR446 does not create statutory thresholds by itself.

What a policy threshold means

Section titled “What a policy threshold means”

In many operational frameworks, roster scoring produces outputs such as:

An organisational policy threshold might state, for example, that patterns above a defined FI or RI level require competent person review before implementation. The specific numbers are set by employers, contracts, or sector standards — not by this site.

Model output vs policy threshold

Section titled “Model output vs policy threshold”
Concept What it is
Model output A modelled estimate from roster inputs — decision-support
Policy threshold An organisational rule on when outputs trigger action
Legal requirement Statutory duties — generally not expressed as FI/RI numbers

HSE RR446 is research underpinning widely used UK methods. See HSE RR446 and the fatigue risk index. It does not make any FI or RI score a legal compliance limit.

How thresholds are used in practice

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Thresholds prompt review — they should not automatically:

  • Approve work regardless of operational context
  • Prove a worker is alert or fit for duty
  • Replace fatigue risk assessment or supervisor judgement
  • Guarantee that a roster is safe

ORR guidance on fatigue risk assessment tools discusses benefits and limitations of roster-based methods in rail — applicable themes for other sectors using similar tools, but rail contractual rules are scoped to relevant work.

When scores exceed thresholds, organisations may require:

Rail and contractual context (scoped)

Section titled “Rail and contractual context (scoped)”

Some rail and infrastructure contracts define formal trigger levels and exceedance processes. This site does not reproduce Network Rail thresholds, Level 1 / Level 2 matrices, or contractual numeric limits.

Organisations should consult current contract requirements and competent advisers. Background familiarity helps readers understand why rail fatigue governance is often more structured — those rules must not be imported into general guidance for other industries.

Section titled “Links to law, guidance, and policy layers”

Understand how layers differ — see law, guidance, standards and policy:

  • Legislation — general duties to manage foreseeable risk
  • Guidance — HSE HSG256, ORR publications — influential but not statute
  • Organisational policy — internal thresholds, reporting rules, approval routes
  • Contractual standards — client-specific requirements on relevant work only

Common misunderstanding

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“An FI below 50 means the shift is safe.”

Model outputs are probabilistic population estimates with known limitations. Policy thresholds are organisational governance tools — they do not measure real-time alertness or eliminate fatigue risk.

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References

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