Decision Fatigue

Decision fatigue is the mental exhaustion that builds after a long period of making choices, causing people to switch to autopilot and take more risks or skip safety steps. It is recognised as an occupational safety hazard because the capacity for careful risk assessment declines as the day progresses.

It is not laziness; it is a predictable limit of human cognitive resources.

Examples include:

• Risk Assessment Defaulting: A supervisor copying yesterday’s Job Safety Analysis (JSA) for a new task late in the day to avoid the cognitive effort of evaluating new, nuanced hazards.
• Superficial Root Cause Analysis: An investigator defaulting to "operator error" after a long string of interviews, avoiding the complex judgment calls required to untangle deeper systemic failures.
• Bypassing Stop-Work Authority: A safety officer observing an ambiguous, borderline hazard late in a shift and defaulting to "it's probably fine" to avoid the complex risk calculation and negotiation required to halt production.

Decision fatigue is widely referenced in HSEQ and fatigue management to design work systems and break schedules that reduce reliance on willpower alone at the end of the day.