IA3 Loss Causation and Incident Investigation

Question 1

Give the quantitative relationship between the type of accidents according the Birds accident triangle

Answer 1

For every,

• 1 x Serious or Major accident e.g. fatality, there were,
• 10 x Minor accidents reported e.g. first-aid injuries
• 30 x Propery damage incidents reported
• 600 x Non-injury/damage (near misses)​

Question 2

What is the meaning of the birds accident triangle?

Answer 2

1. There is a relationship between the reported major accidents and reported less serious accidents/incidents.
2. It proposes that if the number of minor accidents is reduced then there will be a corresponding fall in the number of serious accidents.
3. Help to convince employees the importance of reporting H&S events.

Question 3

List the limitations of using Ratio studies

Answer 3

1. Not every near-miss or minor incident can potentially lead to a major accident.
2. Representative data is neccesary to accurately compare between organisations. Not all events may be recorded.
3. When benchmarking, different loss event definitions will lead to different traingles (e.g. lost time injury versus 3 day absence injuries)
4. When benchmarking, different H&S Culture between organisations.
5. When benchmarking, different industries, with different types of risk.

Question 4

List theories/models of loss causation techniques

Answer 4

1. Accident/Incident ratio studies e.g. Heinrich’s/Bird’s Accident Traingle
2. Bird’s Domino theory (immediate, underlying and root causes)
3. Bird’s Multi-causality theory
4. Reason’s model of accident causation - Swiss Cheese Model (Active and Latent failures)
5. The Bow Tie method (FTA, ETA)

Question 5

Explain the Domino Theory

Answer 5

• Heinrichs domino theory states that all accidents are a result of a chain reaction of events working much like a row of dominoes.
• Heinrich suggested that the removal of one of the key metaphorical dominoes (such as an unsafe act or condition) will stop the chain reaction.
• The model itself focused to heavily on blaming individuals for accidents/incidents
• Updated by Bird &Loftus

Question 6

List the components of the original Heinrich Domino theory

Answer 6

1. domino 1: Ancestry and the worker’s social environment
2. domino 2: The worker’s carelessness or personal faults
3. domino 3: an unsafe act or a mechanical/physical hazard
4. domino 4: the accident
5. domino 5: injuries or loss

Question 7

List the adjustments made by Bird & Loftus to Heinrich’s Domino theory

Answer 7

1. The influence of management and managerial error.
2. Loss could also be production losses, property damage or
   wastage of other assets, as well as injuries.

Question 8

List the components of the Bird&Loftus Domino theory (updated version)

Answer 8

1. domino 1: Lack of Control-Management
2. domino 2: Basic Causes-Origins (personal factors and a job factors)
3. domino 3: Immediate Causes-Symptoms (unsafe acts and unsafe conditions)
4. domino 4: Incident-Contact (an undesired event occurs.)
5. domino 5: People – Property – Loss (result of the accident)

Question 9

Define latent failures and give examples

Answer 9

• Latent failures are contributory factors that may lie dormant for days, weeks, or months until they contribute to the accident.
• Latent failures are made by people whose tasks are removed in time and space from operational activities, eg designers, decision makers and managers.
• Latent failures span the first three domains of failure in Reason’s model.
• Examples: Poor design of plant and equipment; Ineffective training; Inadequate supervision; Ineffective communications; and uncertainties in roles and responsibilities.

Question 10

Define active failures and give examples

Answer 10

• Active failures encompass the unsafe acts that can be directly linked to an accident.
• Usually made by frontline people such as drivers, control room staff or machine operators.
• Example: Human errors, mistakes and rule breaking. for example a train driver error e.g. ignoring the stop signal, causing a train crash

Question 11

In the Swiss Cheese Model most accidents can be traced to one or more of four levels of failure, list these levels of failures

Answer 11

1. Organisational influences (Latent Failure)
2. Unsafe supervision (Latent Failure)
3. Preconditions for unsafe acts (Latent Failure)
4. The unsafe acts themselves (Active Failure)

Question 12

Give a variety of behavioural root cause analysis techniques

Answer 12

1. The 5 Whys method
2. Applied Behavioural Analysis (ABA)
3. Influence and Causal Factor Charting
4. Fishbone or ‘Ishikawa’ Cause & Effect Diagrams.

Question 13

List the possible limitations of multi-causality theories in
accident investigation

Answer 13

1. Complexity of the task (accidents often have multiple
   causes and require in-depth investigation).
2. Specialist skills required

“Management commitment to H&S plays an important role here, quality of investigation process may depend on resources”

Question 14

List the formula for calculating frequency rate

Answer 14

Total number of accidents / total man-hours worked x 1 000 000

Over a year

Question 15

List the formula for calculating Incidence rate

Answer 15

Total number of accidents / Average number of persons employed x 100,000

Over a period of time

Question 16

List the formula for calculating Accident and Incident Severity Rate

Answer 16

Total number of days lost / Total number of man-hours worked in the period x 1000

Question 17

List the formats in which the data gathered on health and safety performance could be presented clearly in a company annual report

Answer 17

1. Pie charts
2. Histograms displaying accident statistics (e.g. bar charts)
3. Line graphs (e.g. trends)
4. Tabular numerical representations such as for example the number of risk assessments completed (e.g. tables on MS Excel)
5. Textual representations with brief summaries of departmental initiatives and case studies.

Question 18

Define unsafe act

Answer 18

HUMAN performance which is contrary to accepted safe practice and which may lead to an accident.

Question 19

Define unsafe condition

Answer 19

PHYSICAL condition of :

• the workplace,
• work equipment
• working environment, etc.

Which is considered unsafe and may lead to an accident.

Question 20

List the steps to take following an adverse event

Answer 20

1. Emergency response
2. Initial report
3. initial assessment and investigations response
4. The decision to investigate (based on potential and actual consequences, setting up the level of the investigation, taking in account personal qualities of the investigation team leader.

Question 21

List the steps to take on the investigation process

Answer 21

1. Gathering of relevant information, asap, witnesses, inspections check, interview techniques.
2. Analysis of information, identifying causation by a systematic approach, use FTA or similar. what and why it happened.
3. Identify control measures, taking account of suitability, effectiveness, reasonable practicability.
4. Produce action plan and implement, report, recommend, review and adjust if necessary.

Question 22

Why do we need to investigate loss events?

Answer 22

1. To identify causality (immediate, underlying and root causes)
2. To prevent recurrence
3. To gather data for trend analysis

Question 23

List the factors influencing the level of investigation

Answer 23

• Severity, both potential and actual
• Actual severity, e.g. risk of compensation claim
• Breach of legal requirements possibility
• Expectation of reporting to the enforcement agency
• Expectation of civil claims/criminal prosecution
• Permit to work involvement, high risk activity involvement

Question 24

List the factors which should be taken in account when analysing the gathered information as evidence

Answer 24

• Organisational factors, culture, peer group pressure, practices
• Job factors, shift patterns, ergonomy, comfort, environment
• Personal factors, drugs, alcohol, training, skills, attitude, experience

Question 25

List the benefits of investigating accidents

Answer 25

• Prevention of future similar events
• Employee morale improvement
• Compliance to legislation
• Safety culture improvement
• Managerial skill improvement