- What behavior-based safety (BBS) is
- Visual map of behavior-based safety
- The logic behind it: antecedent, behavior, consequence
- How to apply BBS in 8 steps
- Example: four weeks of observation on a machining line
- How to give feedback in 60 seconds
- Metrics to track
- Common mistakes and limitations
- Frequently asked questions
What behavior-based safety (BBS) is
Behavior-based safety (BBS) is a method that observes critical behaviors at work, gives feedback on the spot and measures the percentage of safe behaviors, so that exposure to injury drops before an accident happens. It works on what people do. It does not replace hazard elimination or engineering guarding.
The focus on unsafe acts goes back to H. W. Heinrich (1931). The modern approach is built on applied behavior analysis and was developed by authors such as E. Scott Geller and Thomas Krause. Instead of asking people to “pay attention”, it studies what leads a person to act a certain way and changes those conditions.
Visual map of behavior-based safety
The map summarizes the ABC model, the observe-and-feedback cycle, the four-week example and the metrics.
The logic behind it: antecedent, behavior, consequence
BBS uses the ABC model. Every behavior has something that comes before it (the antecedent) and something that follows (the consequence). To change a behavior, you have to change one of the two.
| Element | What it is | Example: cleaning a machine without lockout |
|---|---|---|
| Antecedent | Instruction, tool, layout, deadline, the leader’s example | Lock stored far from the machine; tight output target |
| Behavior | Observable action of the person | Cleans without isolating the energy |
| Consequence | What happens next | Saves 3 minutes now; injury is unlikely and comes later |
Immediate, certain consequences outweigh delayed, uncertain ones. That is why “reminding people of the risk” works poorly: the time saved is certain and the injury is rare. BBS fixes the antecedent (the lock next to the machine) and reinforces the safe behavior with immediate recognition.
How to apply BBS in 8 steps
- Gather the data: accidents, near misses and inspection findings. A well-run accident investigation shows which acts appear among the causes.
- Pick 5 to 10 critical behaviors tied to serious injuries, not to minor rules.
- Define each one so it can be observed: “keeps hands outside the press zone during the cycle”, not “works carefully”.
- Build the checklist with three answers per behavior: safe, at risk or not applicable.
- Train volunteer observers from several areas and levels, not only supervisors.
- Observe for 10 to 15 minutes at the workplace, without recording names. The data belongs to the process, not the person.
- Give feedback on the spot and record what prevented the safe behavior.
- Tabulate every week and take the result to the daily management meeting, with actions to remove the barriers.
Observation fits well into a gemba walk: the leader is already on the floor and can train their eye on specific behaviors.
Example: four weeks of observation on a machining line
Fictional case, to illustrate the calculation. Five critical behaviors, 40 observations of each per week, so 200 behavior observations per week.
% safe = safe observations ÷ total observations × 100
Week 1: 138 ÷ 200 = 69%. Breakdown by behavior:
| Critical behavior | Safe / observed | % safe |
|---|---|---|
| Safety glasses | 36 / 40 | 90% |
| Gloves suited to the task | 34 / 40 | 85% |
| Lifting posture | 24 / 40 | 60% |
| Hands outside the press zone | 22 / 40 | 55% |
| Lockout before cleaning or clearing | 22 / 40 | 55% |
| Total | 138 / 200 | 69% |
The three behaviors below 70% become the priority. Talking to the operators revealed two barriers: the lock was 15 meters from the machine, and the cleaning brush was short, which put the hand close to the press. The team moved the lock next to the machine and bought a long-handled brush.
| Week | Safe / 200 | % safe |
|---|---|---|
| 1 | 138 | 69% |
| 2 | 150 | 75% |
| 3 | 164 | 82% |
| 4 | 176 | 88% |
Week 4 reached 176 ÷ 200 = 88%, close to the team’s 90% target. Note that this rise measures observed behavior, not the number of accidents. Effectiveness is confirmed over time in the injury frequency and severity rates.
How to give feedback in 60 seconds
- Recognize first what is safe: “I saw you locked out the machine before cleaning”.
- Describe what you saw without judging the person: “your hand was inside the press zone”.
- Ask why: “what makes it hard to do it another way?” The answer is the most valuable data from the observation.
- Agree on the next step and log the barrier for management to resolve.
Feedback is never a reprimand. If observation turns into punishment, people start hiding the behavior and the data loses its value.
Metrics to track
- % safe by behavior and by area, weekly.
- Coverage: how many areas and shifts were observed in the period.
- Barriers resolved: how many were removed, and how fast.
- Participation: number of active observers. ISO 45001 requires worker consultation and participation, and BBS helps meet that point.
Show the result on a simple board, as in the visual management model. For machine risk, combine it with the controls described in machine safety under NR-12.
Common mistakes and limitations
- Using BBS to blame the worker. It complements the hierarchy of controls and does not replace it: eliminate, substitute, guard, organize, and only then PPE and behavior.
- A checklist that is too long. Above 10 items, observation turns into paperwork.
- Only supervisors observe. A peer’s eye starts a conversation; the boss’s eye tends to create fear.
- Collecting without acting. If barriers are not removed, the team loses trust.
- Paying bonuses for the number of observation cards. That encourages false entries.
- Treating % safe as the only result. Also track injuries and near misses. One-off training such as TWI helps teach the safe method in a standard way.
Frequently asked questions
What is BBS?
Behavior-based safety: observing critical behaviors, giving feedback and measuring the % of safe behaviors.
Does BBS replace risk management?
No. Hazards are eliminated and controlled first; BBS addresses the behavior that remains.
What is the formula for % safe?
Safe observations ÷ total observations × 100. In the example, 138 ÷ 200 = 69%.
How many behaviors should be observed?
From 5 to 10 critical behaviors tied to serious injuries, defined so they can be observed.
Who should make the observations?
Trained volunteers from several areas and levels, not only supervisors.
Is BBS the same as ISO 45001?
No. ISO 45001 is the OH&S management system standard; BBS is a tool that can support it.
Sources
- GELLER, E. S. The Psychology of Safety Handbook. Boca Raton: CRC Press, 2001.
- KRAUSE, T. R.; HIDLEY, J. H.; HODSON, S. J. The Behavior-Based Safety Process. New York: Van Nostrand Reinhold, 1990.
- HEINRICH, H. W. Industrial Accident Prevention. New York: McGraw-Hill, 1931.
- ISO 45001:2018. Occupational health and safety management systems.
Keep studying: trusted sources and links
- Ministério do Trabalho e Emprego: Normas Regulamentadoras (NRs) (in Portuguese)
- ABEPRO: Associação Brasileira de Engenharia de Produção (in Portuguese)
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About the author
Lean Manufacturing & Behavioral Management Specialist
Over 20 years in the automotive and metalworking industries (GM and Dana), Lean Manufacturing practitioner since 2006. SENAI instructor and mentor in Brazil’s Brasil Mais Produtivo program, delivering consulting, training and audits for 50+ companies, combining quality, productivity and people development.
