Accident Causation and Investigation

Heinrich's Accident Theory

2% unavoidable, 10% unsafe conditions, 88% unsafe acts

Job Safety Analysis (JSA)

An analysis that dissects a repetitive task, whether performed by a person or machine, to determine potential hazards if each action is not performed.

Near Miss Relationship

Behind every major accident there are 1 serious, 29 minor accidents and 300 near misses Recent - 1 serious, 59 minor, 600 close calls

Modern Causation Model - Safety Management Error

First Domino in Modern Causation Model A weakness in the knowledge or motivation of the Safety Manager that permits a preventable defect in the safety program to exist.

Epidemiological Theory

Focuses on industrial hygiene and the casual relationship between environmental factors and disease.

Domino Theory (Heinrich)

one factor in a sequence that may lead to an injury. Each of the factors is dependent on the preceding factor. *An accident occurs only as the result of a personal or mechanical hazard. *The first scientific approach to accident prevention

Heinrich concluded...

that accidents were primarily the result of unsafe acts or unsafe conditions or were unavoidable.

Combination Theory

the actual cause of an accident may be explained by combining many models.

Situational Charateristics

the current state of affairs people are immersed in, where the situation has them driving to work or doing a goal oriented task.

Primary purpose of an accident investigation

to prevent a reoccurrence of the same accident.

Gross Hazard Analysis

Performed to get a rough assessment of the risks involved in performing a task. Typically takes the form of a diagram or table

Heinrich's three E's

"Corrective Sequence Actions" - - Engineering - Education - Enforcement

Accident/Incident Theory (Peterson's Model/Theory)

"Superman Syndrome" - leads a person to believe tat he is invincible or bulletproof, simply because "it won't happen to me or accidents happen to others who don't pay attention." *included ergonomics

Heinrich's Axioms of Industrial Safety

- Management should assume responsibility for safety as it is in the best position to get results. - The supervisor is the key person in accident prevention - Any accident results in direct and indirect costs

Fault Tree Analysis (FTA)

A logic diagram that determines the most probable sequence of events that led to the accident.

Energy Release Theory

Accidents are caused by out-of-control energy. Dr. William Haddon focused on vehicular safety and contributed to seat belt laws, braking systems, and penetration-resistant windshields.

Human Factors Theory (causation model)

Accidents are the result of a chain of events ultimately caused by human error. Causes of human error: 1. Overload - the work task is beyond the capability of the worker 2. Inappropriate Worker Response - to hazards and safety measures, or to incompatible work station 3. Inappropriate Activities - Lack of training and misjudgment of risk.

Failure Modes and Effects Analysis

The first step of a system reliability study. It involves reviewing as many components, assemblies, and subsystems as possible to identify failure modes, and their causes and effects.

Multi-Linear Events Sequencing (MES) Method

Uses a timeline or a chart to display the sequence of events that contributed to or was the direct cause of the accident

Predispositional Characteristics

a person is very susceptible to peer pressure

Systems Theory

a relationship between man, machine systems, and the surroundings, which function as a unit or a whole (system). *The likelihood of a failure increases as the complexity increases.

Behavior Theory

also known as BBS, Behavior-based Safety, involves a focus on positive consequences, data collection, and common goals of the employee and managerial involvement in the process

Accident

any unplanned , uncontrolled event that could result in personal injury or property damage.