1. Purpose
  2. General
  3. Responsibility
  4. Procedure
  5. References
  6. Attachments

1. Purpose

The purpose of this guide is to define a consistent approach to the detailed investigation of accidents, incidents and near miss incidents (accidents) with the aim of achieving a high quality of analysis and reporting.

For the purpose of this procedure accidents, incidents and near miss accidents will be referred to as incident(s) unless otherwise stated.

2. General

The proper investigation of incidents and the subsequent reporting of findings and recommendations is an essential part of Safety, Health, Welfare and Environmental management on Company construction sites.

Investigation findings may contribute to Company’s effort to try to prevent similar occurrences from happening in the near future. They will furthermore enhance Company’s continuous efforts of the preservation of human life, material assets and the environment and it will improve Company’s safety performance in construction execution.

3. Responsibility

3.1 Project Construction Manager

The prime responsibility for incident investigation rests with the Company Project Construction Manager. He may delegate this responsibility to the Company Site Safety Engineer or to another key member of his organization if he deems this best for the quality of the investigation.

At the discretion of the Project Construction Manager, a detailed investigation as per this guide may be held and an investigation team may be formed if the complexity or other characteristics of the incident warrant so.

Alternatively the Project Construction Manager may be instructed by the home office or by a third party, i.e. the client or local authorities to have a detailed investigation conducted.

3.2 Investigation

It is the responsibility of the investigator/the investigation team to conduct the investigation following the procedure as described in this guide through and including the distribution of the investigation report.

3.3 Site Safety Engineer

It is the responsibility of the Site Safety Engineer to follow-up on the implementation of recommendations related to site assigned actions and to report the status to the home office Manager of Safety.

3.4 Home Office Manager of Safety

It is the responsibility of the Manager of Safety to follow-up on the implementation of recommendations related to home office assigned actions and to keep a status record of site and home office implementations.

4. Procedure

4.1 Levels of Reporting

4.1.1 Standard Reporting

All incidents shall be reported following the instructions in reference 5.1

For applicable forms to be used, see reference 5.2 and 5.3.

4.1.2 Detailed Reporting

It is at the discretion of the Project Construction Manager to initiate a detailed investigation including reporting in case of:

  • a serious and/or complex incident;
  • any incident with a potential for serious impact on personnel, assets or environment.

Subject initiative will be based on subjective personal reasons or as the result of an instruction from the home office or a third party.

4.2 Preservation of Evidence

The first action to be taken, after an incident has occurred, is to prevent further injury and arrange for any necessary medical treatment. Furthermore measures shall be taken to prevent the situation from escalating and causing further damage. Details can be found in reference 5.1.

The second action is to preserve the evidence at the location of the incident. The location should be left unchanged, to the extent possible, until the investigation team has inspected it. If this is not possible, photographs, video pictures or even sketches should be made of the scene. Access to the scene may be limited or fully restricted and adherence to authority requirements shall be observed at all times.

A preliminary assessment of the incident should be made to identify the extend of injury or damage, and any potential for escalation.

Damaged components or equipment should be lodged in a secure place pending more detailed analysis.

4.3 Investigation Team

In case the Project Construction Manager has decided to form an investigation team, typically such team would be composed from the following personnel:

  • Project Construction Manager or his delegate;
  • Company Site Safety Engineer
  • Construction Superintendent and/or the relevant Construct Discipline Specialist;
  • Subcontractor Safety Representative(s);
  • Client Representative and/or third party personnel, as required.

The actual size and composition of an investigation team will depend on the circumstances.

4.4 Investigation Process

4.4.1 Level of Investigation

The level of investigation is set by the Project Construction Manager or by third party requirements. The basic point of reference is the actual and/or potential severity of the event.

4.4.2 Scope

The scope of the investigation should be such as to achieve the following primary aims:

  • to identify the root causes of the incident such that actions can be taken to prevent recurrence;
  • to review the application of management practices and their impact on SHWE;
  • to establish the facts surrounding the incident for use in relation to potential insurance claims or litigation;
  • to meet relevant statutory and Company requirements on incident reporting.

This may necessitate review of aspects remote from the location and time of the incident.

4.4.3 Timing

An investigation should be carried out as soon as possible after an incident. The quality of evidence can deteriorate rapidly with time, and delayed investigations are usually not as conclusive as those performed promptly. A prompt investigation is also a good demonstration of management commitment.

4.4.4 Background Information

Appropriate background information should be obtained before visiting the incident location. Such information could include:

  • procedures for the type of operation involved;
  • records of instructions/briefings given on the particular job being investigated;
  • location plans;
  • command structure and persons involved;
  • messages, directions etc., given from base/head office concerning the work.

4.4.5 Investigation Method

The method of conducting an investigation consists of the following activities:

  • fact finding;
  • inspecting the location;
  • gathering or recording physical evidence;
  • interviewing witnesses;
  • reviewing documents, procedures and records;
  • conducting specialist studies (as required);
  • resolving conflicts in evidence;
  • identifying missing information;
  • recording additional factors and possible underlying causes including human factors (TRIPOD approach).

During the initial stages of every investigation, investigator(s) shall gather and record all the facts that may be of interest in determining causes.

Investigator(s) shall be aware of the danger of reaching conclusions too early, thereby failing to keep an open mind and considering the full range of possibilities.

Checklists are very useful in the early stages to keep the full range of enquiry in mind, but they cannot cover all possible aspects of an investigation, neither can they follow all individual leads back to basic causal factors. Their limitations should be clearly understood.

For a checklist see Attachment 1.

4.4.6 Interviews

People should be interviewed singly and be asked to go step-by-step through the events surrounding the incident, describing both their own actions and the actions of others.

The value of a witness’s statement can be greatly influenced by the style of the interviewer, whose main task is to listen to the witness’s story and not to influence him/her by making comments or asking leading questions. This requires patience and understanding. If the investigation is a team effort, great care should be taken not to make a witness feel intimidated by too many interviewers. Experience has shown that interviews can be effectively conducted by a pair of interviewers and if appropriate, the witness could be accompanied by an independent “friend”.

It should be remembered that an investigation team is often seen in a prosecuting role, and there may be a reluctance to talk freely if people think they may incriminate themselves or their colleagues. An investigator is not in a position to give immunity in return for evidence, but must try to convince interviewees of the purpose of the investigation and the need for frankness.

At the end of an interview the discussion should be summarized to make sure that no misunderstanding exist. A written record should be made of the interview and this should be discussed with the witness to clarify any anomalies. Any anomalies in the statement or conflicts with other evidence should be clarified.

4.4.7 Records and Procedures

Documentation such as “as-built” drawings, inspection records, instrument and tachograph records, printouts, log sheets/books, maintenance records, work permits and load/time sheets may provide information relevant to the investigation.

Written instructions and procedures provide evidence of pre-planning and individual responsibilities. The investigation should try to establish the extent to which these procedures and instructions were understood and acted upon, as these can indicate the effectiveness of training and supervision. The relevance and extent of application of procedures should be assessed during the investigation.

4.4.8 Conducting Special Studies

Incidents of an involved or complex nature often require the analysis of specialists to determine causes of failure. Aircraft crashes, crane failures and explosions are examples of incidents, requiring specialist advice. This should be rapidly identified and the specialists should be involved early in the site assessment.

4.4.9 Conflicting Evidence

It is not unusual for different witnesses to give different accounts of an incident. Human memory can be unreliable and, even if not motivated by self-protection or other subjective arguments, one person’s recollection of an incident can differ from another’s in quite important details. Investigators should note any significant differences in accounts of an event. Faced with conflicting witnesses’ statements, investigators should look for the similarities between the statements and commonality with other evidence. The objective is to use the evidence to understand the incident and not to prove the accuracy of individual statements, nor to apportion blame.

4.4.10 Identifying Missing Information

As the investigation progresses, the investigator(s) should begin to identify the sequence of events and concentrate efforts on increasing their knowledge of areas of uncertainty.

4.4.11 Underlying Causes and Human Factors

As the extent of physical factors involved in an incident becomes clear, the investigator(s) should shift the emphasis of their investigation and questioning to the underlying causes and to the reasons for peoples’ actions. This will allow for ease of assessment when analyzing the incident (TRIPOD approach).

4.5 Sequence of Events

In the fact finding stage of an incident investigation, it is crucial to obtain all facts essential to the understanding of the incident. This implies back tracking from the initial facts found, to discover the reasons behind them. Without a structure for identifying and following leads, it is difficult to ensure that the full scope of the investigation has been covered.

Gaps that are left in the event sequence should be reviewed to identify alternative scenarios to complete the sequence. In doing this it may be helpful to consider the human factors sequence.

4.5.1 General

The approach of tabulating events and then ordering them by date, time and place is an essential stage in establishing the sequence of events.

4.5.2 Incident Investigation Matrix

The construction of a diagram or matrix showing the connections between the various events and conditions leading up to the incident has proved to be a useful technique in the investigation process, especially for more complex incidents.

The literature shows a variety of approaches in depicting incidents and their preceding conditions. Company has adopted the TRIPOD matrix approach as the standard. Refer Attachment 2.

Subject matrix should give the answers to the following question:

“What prior events or conditions were necessary for this incident to happen?”

The incident matrix consists of the following columns:

  • incident tree;
  • defences;
  • unsafe acts;
  • pre-conditions;
  • latent failures;
  • fallible decisions;
  • recommendations.

For definitions refer to Attachment 2.

4.6 Analysis of Findings

The purpose of analysis is to establish the critical events and the underlying causes of the incident such that corrective measures can be taken to prevent future incidents. This requires investigators to have a clear understanding of the cause and sequence of activities and why one event or situation progressed to the next.

Incident causation studies clearly identify that an incident is caused by a chain of events. These can be identified at differing stages in the incident causation sequence.

Restricting the investigation to the unsafe acts or active failures will automatically result in the conclusion that “human errors” caused the incident. In most cases “human errors” can occur because of the dormant “latent failures”. The latter are system shortcomings of a structural nature.

Identifying and correcting these latent failures rather than merely correcting the active failures induced by them (symptoms), is more effective in meeting the ultimate objective of the investigation, namely to improve the overall SHWE performance.

4.7 Identification of Recommendations

The investigation process should identify actions to prevent recurrence. This can best be achieved by addressing the unsafe acts and unsafe conditions, and by identifying and correcting the latent failures. Not all causes can be completely eliminated, and some may be eliminated only at prohibitive cost. Some recommendations will therefore be aimed at reducing the risk to a tolerable level, while others will be aimed at improving protective systems (the defences) to limit the consequences.

All recommendations shall be in the form of measurable action items with clearly defined action parties and a time scale for implementation.

4.8 Investigation Report

4.8.1 Format

The investigation report is a presentation of all findings, includes the recommendations by the investigator(s) and the necessary follow-up action(s). The report shall follow the standard table of contents as shown in a Attachment 3. The Incident Investigation Matrix or TRIPOD Incident Analysis and any supporting evidence such as photographs, sketches, a completed form (ref. 5.3) etc. shall be attached to the detailed investigation report.

4.8.2 Legal Assistance

If incident reports are being compiled that may be required by authorities outside the company, it is strongly recommended that legal advice is sought in the preparation of the report. Legal advice should also be considered if third parties, including other authorities than those directly competent in respect of the incident, request to be provided with copies of the report. Each such request shall be considered on a case by case basis taking into consideration the potential risks and exposures for Company, its directors and employees for possible criminal or civil liability.

Seeking legal advice shall be done with prior consultation of Company’s counsel.

4.8.3 Management Review and Endorsement

If for the incident an investigation team has been formed its detailed investigation report shall be reviewed by:

  • Project Construction Manager;
  • Home Office Manager of Safety;

as a check on the completeness and quality of the investigation and to obtain endorsement of the recommended actions assigned to the site respectively to the home office.

4.8.4 Distribution

Detail investigation reports shall be completed and distributed within 5 working days after the incident.

As a minimum the following personnel shall be included on the distribution list:

  • Investigator(s);
  • Project Manager;
  • Project Construction Manager;
  • Site Safety Engineer (if not the investigator);
  • Home Office Manager of Safety;
  • Home Office Manager of Construction;
  • Management of the subcontractor(s) involved in the incident.

Furthermore the client and/or the authorities may require a copy. Reference is made to paragraph 4.8.2 for legal awareness.

4.9 Follow-up

4.9.1 Communication of Investigation Findings

Relevant findings and conclusions of incident investigations should be given as wide a distribution as practicable, to maximize the lessons learnt.

Discussions in monthly Safety Committee Meetings, weekly toolbox meetings, weekly Construction Management meetings and home office SHWE meetings should be used to maximize the benefits from the learning points of the incident investigation and help achieve the objective of preventing similar incidents.

4.9.2 Implementation of Recommendations

Recommendations should be discussed on a formal basis with action parties for agreement on the action required and the related time-schedule for implementation. Review and endorsement shall be as per paragraph 4.8.3.

It is the responsibility of the Site Safety Engineer to follow-up on the implementation of recommendations related to site assigned actions and to report the status to the home office Manager of Safety.

It is the responsibility of the Manager of Safety in the Home Office to follow-up on the implementation of recommendations related to the home office assignee actions. These actions will normally be of a structural nature, might require adjustment of procedures/ guides or standards or even require additional training of personnel.

4.9.3 Monitoring of Implementations

It is the responsibility of the Manager of Safety to monitor all site and home office action implementations by keeping a status record. For this reason all required actions with their agreed completion dates and responsible individuals shall be registered in the departmental action list.

If the action involves adjustment of or the preparation of new procedures, guides and/or standards, audits shall be considered to verify proper adherence to these new rules. This verification may be conducted as part of a more general audit or as a subject specific audit.

Depending on the results of these audits a second cycle of recommendations may evolve.

5. References

  Document Number Title Level
5.1 BN-G-UC004 Field Construction Safety, Health, Welfare and Environmental Program 5
5.2 RG26003 not available First Report of Injury 5f
5.3 RG26004 not available Accident/Near Miss Investigation Report 5f

6. Attachments

  1. Incident Investigation Checklist
  2. Tripod Incident Analysis
  3. Report Front Sheet and Table of Contents

Attachment 1. Incident Investigation Checklist


This checklist has been prepared to assist in undertaking the investigation in a structured way. Although detailed, this list is definitely not exhaustive.

The checklist addresses subjects/questions in the following five categories:

A. people;
B. environment;
C. equipment;
D. procedures;
E. organization.

To ensure that all relevant facts are uncovered, the broad and open questions of who?, what?, when?, where?, why?, and how? should be asked. Leading questions shall be minimized if not avoidable.

Regularly summarizing the answers is advisable to avoid misunderstandings and unnecessary disputes in the report preparation phase.

A. People

  • workmanship education
  • years with current employer
  • years of experience
  • weeks/months on site
  • certificates (skills, cranes, vehicles, etc.)
  • safety training
  • induction program
  • toolbox meetings
  • site rules & safety regulations
  • working hours, overtime
  • family circumstances
  • social problems
  • drugs
  • alcohol
  • language barriers
  • recent changes : family, supervision, instructions
  • instructions received
  • distracting events
  • work pressure
  • sequence of activities prior to incident
  • impact of other individuals
  • physical/mental condition prior to incident
  • injury
  • treatment
  • medical/first aid response time
  • familiarity with tools and/or equipment
  • level of supervision
  • any safety inspection warnings
  • witnesses
  • presence of unauthorized people
  • location key personnel, activities prior to incident

B. Environment

  • weather
  • daylight
  • artificial light/blinding
  • work space/accessibility/congestion
  • obstructions
  • wet/dry surface
  • restricting personal safety equipment
  • unacceptable safety rules
  • distracting fumes/smells
  • distracting noise level
  • recent workspace modifications
  • stability of surface for fixing equipment
  • state of housekeeping
  • evidence of spills or releases
  • evidence of excessive forces
  • presence/absence of warning signs/notices
  • uncontrolled energy flows
  • barriers to prevent incident, why not adequate

C. Equipment

  • proper tools/equipment used
  • tool/equipment inspections
  • safety protections in place
  • required personal protective equipment used
  • green tagged scaffolds
  • tachograph (vehicles)
  • load curves (cranes)
  • maintenance status of tools
  • equipment design capacities
  • equipment failures
  • any inappropriate use of equipment
  • position of equipment in relation to other equipment/facilities

D. Procedures

  • availability procedures
  • availability manuals
  • procedures followed
  • familiarity with procedures
  • any recent changes in procedures
  • validity of procedures issued
  • permit system applicable
  • permit for relevant activity
  • describe pertinent instructions
  • underlying causes (defective procedures)
  • job description available
  • Job Safety Analysis

E. Organization

  • relevance/input by safety program
  • line of command
  • briefing/debriefing at shift change
  • underlying causes
  • operational deviations
  • damage control (personnel, equipment, environment)
  • recent organizational changes.

Attachment 2. (Example) Tripod Incident Analysis -

click image for pdf ..


Incident Tree sequence of events prior to and during incident including relevant information of the injured.
Defences any feature present to minimize the risk of an incident to occur or to minimize the consequences of an incident.
Unsage Acts any act by an individual that could create an incident.
Pre-conditions circumstances existing prior to incident.
Latent Failures one or more of the eleven (11) General Failure Types, being a system shortcoming and latent cause of an incident.
Fallible Decisions decisions made and being the initiators of General Failure Types.

Attachment 3.


Company Name:


Project name:

Project No.:



Tripod Incident Analysis:








Project Construction Manager



Manager Safety


Dates of Investigation:



Table of Contents

  1. Summery of Report
  2. Time, Place and Date of Incident
  3. Weather Conditions
  4. Details of Persons
  5. Details of Damage
  6. Events Leading up to the Incident
  7. Description of the Incident
  8. Result of the Investigation
  9. Conclusions
  10. Recommendations for Avoiding a Re-ocurrence
  11. Appendices