Assessing and Preventing Serious Incidents with Behavioral Science: Enhancing Heinrich’s Triangle for the 21st Century

McSween et al. (2017) rewrote an old safety rule called Heinrich's triangle. The 1930s version said for every major injury you have 29 minor ones and 300 near-misses.

They added two new slices: leadership failures and system breakdowns. The paper explains how to fold these checks into your BBS audits.

The authors show that tracking only worker behavior misses the big stuff. You also need to watch how bosses set goals and how the system rewards shortcuts.

When you log these upper-level failures, you can stop serious injuries before they happen.

Johnson et al. (1994) beat them to the punch. That team used Deming's quality cycle to flag system failures. McSween keeps the same spirit but swaps the Deming wheel for an updated triangle.

Johnson et al. (2024) takes the idea further. They replace punitive discipline with OBM performance-recovery. Both papers push BBS past 'blame the worker' toward 'fix the system.'

Weatherly (2019) moves the lens into hospitals. It keeps McSween's coaching theme and adds steps to lock the new habits into everyday clinical routines.

If your safety walk only records gloves worn or hard hats on, you are still staring at the small end of the triangle. Add two quick columns to your checklist: 'Leadership cue given?' and 'System barrier noted?' When a supervisor rushes a job or a guard is missing, mark it. Share these counts at the weekly meeting. Over time you will see the real path to serious harm and can act before blood is spilled.