According to the UN Global Compact, around 2.8 million workers die from occupational accidents or work-related diseases, and around 374 million experience some form of non-fatal accidents at the workplace.

Accidents don’t just “happen” They’re often the result of a chain of events where minor issues line up just the right way (or you can call it the wrong way). You have probably watched the movie "The Final Destination." A workplace accident can also feel like a grim sequence of mishaps that, piece by piece, lead to a disastrous result. 

These events are rarely a matter of fate (seemingly, though) but a mix of overlooked hazards, equipment failures, and human errors that, when combined, lead to severe consequences.

Human error and random chance frequently merge to create a “perfect recipe for disaster” that pops up as accidents, such as:

1. Workers lack workplace health & safety awareness training 
2. Workers might miss safety steps in their routines
3. Assume a task is safe & there is nothing to be cautious about
4. Not maintaining a checklist to ensure all SOPs are followed religiously
5. Neglecting routine and regular inspection of equipment in a facility
6. Gaslighting issues and underestimating their consequences

A minor oversight can lead to serious injury in a workplace when combined with risky environmental factors like faulty wiring or loose guardrails. These mistakes carry even higher stakes in environments where powerful equipment and heavy loads are routine.

This blog post will help you discover everything about accident root cause analysis. Let’s start by discovering accident root cause analysis and why there is a need for a systematic approach to curb the likelihood of future accidents. 

What is Root Cause Analysis (RCA)?

Accident Root Cause Analysis (RCA) is a structured, analytical method to uncover the fundamental reasons behind incidents or failures (particularly in complex systems like aviation, workplace environments, and healthcare). 

Unlike surface-level investigations, which focus on the immediate cause of an accident, RCA is designed to investigate the more profound, often interrelated contributing factors that trigger a “snowball effect” and lead to accidents. 

Understanding the depth and complexity of accident root cause analysis at the workplace makes attending OSHA-compliant accident and incident investigation training crucial. The goal of RCA in accident investigation is to identify and address the actual sources of failure rather than merely treating visible outcomes. This will enhance system reliability and prevent the recurrence of similar events.

Accident Root Cause Analysis (RCA) is a rigorously scientific process grounded in systematic examination and peer review rather than a simplistic view of accidents as mere acts of nature or fate. 

Unlike metaphysical interpretations that see incidents as unavoidable, RCA treats every workplace accident as a sequence of causative factors that can be identified, analyzed, and mitigated. 

This analytical approach relies on thorough investigation and evidence-based reasoning, allowing safety teams to scrutinize each contributing element precisely. RCA is built on the principle that: 

Accidents are not random but result from identifiable issues within processes, equipment, or human actions.

In workplace accident analysis, RCA is integral for dissecting the deeply interrelated systems interacting with each other, including: 

1. Humans
2. Procedures
3. Equipment

By systematically examining these elements, their relations, hierarchy, and weight (weight in terms of contributing factors of accident), RCA identifies root causes. 

These root causes are factor(s) that, if removed or altered from the chain of events, would have likely prevented the incident.

One critical distinction in RCA is that it avoids the "band-aid" approach (a reactive or short-term approach) of addressing symptoms or superficial issues. 

For example, while repairing a faulty machine after an incident, instead of addressing the immediate cause of an accident, RCA pushes stakeholders further to:

1. Explore why the machine failed in the first place
2. Examine possible gaps in maintenance protocols
3. Evaluate quality assurance or operator training

This systematic and well-structured approach ensures that corrective actions are targeted at preventing the underlying issue rather than just alleviating its effects.

RCA and Theory of Causality

The Theory of Causality (given by Aristotle and David Hume), also known as the theory of cause and effect, describes the relationship between cause and effect. 

It is central to the Root Cause Analysis (RCA) process and is foundational to understanding workplace accidents. In essence, causality theory states that: 

“Every EFFECT (such as an accident) has a definable set of CAUSES and sub-cause(s).”

These causes are further categorized as:

1.    Direct Causes

2.    Indirect Causes

3.    Interdependent Causes

RCA applies this principle by systematically tracing each incident's root causes and examining how different variables and conditions align to produce a specific outcome. 

This scientific approach to causality allows investigators to view accidents not as isolated events but as results of interconnected factors within a system*.

*A System is the part of an environment/universe under consideration. Everything beyond the boundary of a system is called the Surrounding. Sometimes, the cause can be hidden in the surroundings instead of the system itself and influence as an external factor in systems that are not isolated. 

Read the next section of this blog to discover the system's relationship to its surroundings in detail as environmental root causes.

In Accident Root Cause Analysis (RCA), improving causal determination systems requires recognizing that causation is Quantitative rather than Qualitative. 

This shift means identifying root causes should rely on measurable data and statistical evidence rather than subjective descriptions or assumptions.

For example, rather than simply noting that "poor maintenance" was a factor in equipment failure, an RCA approach would quantify maintenance frequency, failure rates, and operational conditions to determine the precise impact of maintenance practices on the incident. 

This quantitative approach helps in:

1. Strengthening the validity of findings
2. Reducing the risk of bias
3. Enabling a more accurate prioritization of corrective actions

In RCA, causality is often categorized into several layers, such as immediate causes, underlying causes, and root causes. 

1. The immediate causes of an accident are the apparent triggers, such as a mechanical failure or procedural lapse. 
2. The underlying causes of an accident go deeper, often including inadequate training or flawed design. 
3. The root causes of an accident represent the most profound, foundational issues that, if corrected, would prevent similar accidents. 

To reach the root causes, it is necessary to discover the immediate and underlying causes that serve as a starting point to initiate investigation.

For example, an equipment failure in a manufacturing plant might be caused by a specific worn component, but the root cause could be traced back to inadequate maintenance schedules. 

Therefore, the cause-and-effect relationship in RCA extends beyond the immediate visible issue. It provides a more comprehensive and holistic understanding of how the failure occurred within the broader system. 

Basic Types of Root Causes

Different causes of workplace accidents need to be approached differently. These causes can be segmented into three general categories that lead to any particular incident.

1. Environmental Root Causes

Target: Reduce physical hazards and improve workplace conditions.

Reason: Environmental factors create underlying risks that can lead to incidents if not managed, as they directly impact workers' ability to perform tasks safely.

Environmental root causes refer to external conditions and physical factors within the workplace that contribute to accidents. These include unsafe equipment design, lighting issues, temperature extremes, noise levels, or hazardous materials present in the work environment. 

Environmental factors are particularly significant because they influence how tasks are performed and equipment and personnel interact with their surroundings. 

For example, a poorly ventilated area may accumulate harmful fumes, creating a risk for respiratory incidents or chemical reactions. Addressing environmental root causes requires focusing on facility layout, engineering controls, and adherence to standards designed to mitigate environmental hazards in high-risk settings.

2. Individual Root Causes

Target: Minimize human error through targeted training and workload management.

Reason: Factors like fatigue (a significant factor in aviation accidents), insufficient training, or stress affect task performance. It makes personnel more prone to error in complex or high-risk tasks.

Individual root causes are factors that stem from workers' personal actions, decisions, or errors. These may include lack of training, improper skill application, fatigue, or personal risk-taking behavior. 

Technical analysis of individual root causes goes beyond blaming workers. It evaluates how workload, repetitive shifts, cognitive demands, and stress affect human performance. 

By examining human error rates and performance metrics data, RCA identifies specific areas where training or procedural adjustments can reduce the likelihood of error to curb the potential for incidents.

3. Organizational Root Causes

Target: Strengthen safety policies and organizational culture to prioritize risk mitigation.

Reason: Organizational-level factors, such as inadequate SOPs or poor communication, create systemic vulnerabilities that can increase the likelihood of workplace accidents.

Organizational root causes are linked to structure, policies, and culture. This includes issues such as:

1. Inadequate Standard Operating Procedures (SOPs)
2. Insufficient resource allocation for safety
3. Ineffective communication channels
4. Poor leadership and toxic work culture
5. Lack of enforcement of safety protocols

Technical analysis in this category assesses how organizational decisions and safety practices contribute to accident risk. For instance, if safety training is insufficient or not conducted regularly, it reflects a systemic issue that increases vulnerability across the organization. 

Addressing organizational-level issues includes changing the policy to enforce safety as an integrated operational and cultural framework.

Why Conduct a Root Cause Analysis?

Conducting an Accident Root Cause Analysis (RCA) goes beyond surface-level fixes by targeting the fundamental causes of accidents, which is critical for continuous improvement in high-risk environments. 

By addressing these root causes, organizations can significantly reduce recurring incidents and improve operational resilience. 

Preventing Future Incidents Through Systemic Improvements

One of the core benefits of RCA is its ability to prevent similar incidents from recurring. According to the Occupational Safety and Health Administration (OSHA), organizations implementing proactive incident analysis, including RCA, can significantly reduce workplace injuries to a notable extent compared to those addressing only immediate hazards. 

By identifying and mitigating underlying risks, RCA systematically lowers the probability of future accidents, especially in high-risk industries like construction, chemical, and industrial manufacturing.

Enhancing Workplace Safety and Compliance

RCA is critical in establishing a safer workplace by addressing underlying risk factors often missed in routine inspections. RCA ensures a comprehensive risk management approach by identifying

1. Weaknesses in safety protocols
2. Equipment maintenance schedules
3. Degree of compliance standards

The National Safety Council (NSC) has created a Supervisors’ Safety Manual for accident reporting and analysis, which requires organizations to implement rigorous RCA processes in their safety programs. 

Creating an incident report is the first step towards systematic RCA, which can be evaluated and further branched out.

Ensuring a Culture of Accountability

Root cause analysis is critical in creating an ecosystem of moral codes, ethics, hierarchy, liabilities, and responsibilities to ensure accountability. 

By involving multiple stakeholders in RCA, including safety officers, operational managers, and equipment operators, the process encourages a shared responsibility for identifying and addressing risks. 

Increasing Operational Efficiency and Reducing Costs

An often-overlooked benefit of RCA is its positive impact on operational efficiency and cost reduction. Addressing root causes can prevent repetitive maintenance costs or production delays. 

A detailed RCA might reveal that inevitable equipment failures, which seemed random, were due to systemic maintenance lapses. By correcting these root causes, organizations reduce costly unplanned downtime and improve productivity. 

Supporting Continuous Improvement and Knowledge Retention

RCA is not a one-time solution; it creates a solid data-driven foundation for continuous improvement. Documenting root causes and corrective actions creates a valuable knowledge base that can be referenced and built upon over time. 

This knowledge base can help create a valuable database to run predictive analytics using modern AI and ML tools. This ensures that lessons learned from past incidents are retained within the organization and avoided in the future.

RCA Categories

Root Cause Analysis (RCA) is not a one-size-fits-all approach; it involves various methodologies, tools, and techniques that address different fields and objectives. 

According to the National Association of State Mental Health Program Directors, RCA principles are generally classified into five main categories:

1.    Safety-Based RCA

Safety-based RCA is designed to identify the root causes of safety-related failures, accidents, or incidents impacting occupational health. This approach examines factors compromising worker safety, such as procedural lapses, hazardous conditions, or equipment-related issues.

2.    Production-Based RCA

Production-based RCA is primarily used in quality control and manufacturing. It investigates the root causes of defects within manufacturing processes or end products. 

This approach identifies and addresses issues affecting production quality, such as equipment malfunctions, material inconsistencies, or procedural errors.

3.    Process-Based RCA

Process-based RCA extends beyond production and focuses on broader business or operational processes. This method addresses inefficiencies, workflow bottlenecks, or systemic issues that impact overall process effectiveness. 

It is used widely in service and business environments to optimize workflows by identifying root causes related to procedural or organizational factors.

4.    Failure-Based RCA

Rooted in failure analysis, failure-based RCA is typically employed in engineering and maintenance. 

This approach investigates the root causes of equipment or system failures. It focuses on material fatigue, design flaws, or maintenance deficiencies to ensure equipment reliability and longevity.

5.    Systems-Based RCA

Systems-based RCA combines multiple RCA methods and incorporates insights from change management, risk management, and systems analysis. 

This comprehensive approach examines how different system elements interact and identifies root causes across complex, interconnected processes.

Steps to Conduct Root Cause Analysis

Let’s go through the step-by-step process of how Root Cause Analysis is performed.

Step 01: Define the Scope

01-A: Identify the Specific Incident – Clearly outline the event or issue you aim to investigate. Narrowing the scope allows the RCA to focus on finding the actual root cause of the specific problem.

01-B: Set Boundaries—Determine which factors are relevant to the incident. For instance, if an employee slips on spilled oil, the RCA should only consider slip-and-fall incidents involving oil to avoid diluting findings with unrelated incidents. This specificity enhances accuracy in identifying root causes.

Step 02: Select a Team

02-A: Assemble a Diverse Group – Include employees with experience in the relevant processes and the environment in which the incident occurred. The team should ideally include individuals from different departments and perspectives to ensure a holistic approach.

02-B: Assign Clear Roles—Designate roles within the team, such as lead investigators, note-takers, and subject-matter experts, to ensure efficient and organized collaboration.

Step 03: Organize Data

03-A: Develop a Detailed Timeline – In-depth incident root cause analysis includes outlining each event leading up to the incident in a precise sequence. This timeline is a visual aid, highlighting key points where processes might have failed.

03-B: Gather Supporting Documentation – Collect all relevant records, including maintenance logs, incident reports, SOPs, and training records. This comprehensive data set provides a basis for accurate analysis and helps uncover contributing factors.

Step 04: Identify Contributing Factors

04-A: Analyze Each Event on the Timeline – For each event, ask “why” it happened, moving backward from the incident to identify contributing factors. For example, if equipment failure contributed to the accident, ask why the equipment failed (e.g., lack of maintenance or a design flaw). 

*Jump to Step 05-A to discover the importance of WHY.

04-B: Document Contributing Factors – Organize contributing factors by type (e.g., human error, equipment, environmental), allowing the team to see patterns and potential interdependencies.

Step 05: Determine Root Causes

05-A: Apply the “5 Whys” ‘Technique – For each contributing factor, continue to ask “why” instead of repeating the debate of “who” until you reach a root cause. This technique helps dig deeper to reveal the underlying issues.

A fishbone diagram (image below) is used as an RCA template to ensure that all the aspects leading to why are visited before concluding.

05-B: Validate Findings—Confirm that the identified root causes are specific, actionable, and relevant to the scope of the analysis. A single root cause may link to multiple contributing factors.

Step 06: Create a CAPA Plan (Corrective and Preventive Action)

06-A: Develop Corrective Actions – Based on root causes, define immediate corrective actions to eliminate current hazards and prevent recurrence in the short term.

06-B: Establish Preventive Actions—Design preventive measures to address systemic issues identified in the RCA. This may include:

1. Revising SOPs
2. Implementing additional training
3. Improving maintenance schedules

06-C: Document the CAPA Plan – Create a detailed CAPA plan with assigned responsibilities, timelines, and measurable goals to ensure accountability and effective implementation.

Step 07: Review and Monitor Changes

07-A: Assign Responsibilities – Designate team members or managers to oversee the implementation of corrective and preventive actions and ensure all tasks are completed on schedule.

07-B: Schedule Follow-up Reviews—There will always remain room for improvement. Conduct periodic reviews of the corrective and preventive measures to gauge their effectiveness. Adjust the CAPA plan based on these reviews to refine safety measures continually.

07-C: Measure Success – Track incident rates, compliance metrics, and other indicators to measure the impact of changes implemented. This feedback loop is critical for verifying the long-term effectiveness of the RCA and CAPA plan in preventing similar incidents.

Importance of RCA Training

Attending a well-structured and supervised Root Cause Analysis (RCA) training goes beyond “just” theory. It’s more about equipping and training employees to:

1. Remove psychological biases in the investigation
2. Conduct thorough investigations to evaluate incidents systematically
3. Identifying immediate causes and underlying issues
4. Use modern digital tools to leverage data that aids in the investigation

Our OSHA-compliant RCA training is designed to match both Canadian Federal and Provincial Occupational Health and Safety Standards. 

Are you interested in building a culture of accountability and safety? Check out our accident and incident investigation training and learn to look beyond symptoms for lasting solutions. 

Our comprehensive training programs aim to equip professionals with all the required skills to make workplaces better and safer for themselves and their co-workers.

Conclusion

We hope you fully understand accident root cause analysis (RCA) and how root cause investigations are performed to find the accurate cause of the incident. 

These causes or issues are then fixed to avoid future accidents. A successful RCA aims to approach the root causes instead of systematically asking surface-level questions. 

This is more complex than it sounds. Going to the core of a problem and finding solutions require a lot of practice and applying the right approach in the right direction. 

Don’t forget to check out our OSHA-compliant accident and incident investigation training, designed by industry experts to enhance workplace health and safety awareness. 

FAQs

What are the 5 steps of root cause analysis?

The five steps of RCA involve defining the scope of the issue, selecting an investigation team, organizing data to create a timeline, identifying contributing factors, and determining the root causes. Each step systematically uncovers underlying issues for targeted corrective actions.

What are the 5 whys in accident investigation?

The "5 Whys" is a technique where investigators ask "why" five times (or as many as needed) to drill down from symptoms (events) to root causes. This approach helps uncover more profound and deeply interdependent causes contributing to the incident.

How do you do an excellent root-cause analysis?

A good RCA requires a clear scope, thorough data collection, and a systematic approach to identify all contributing factors. Involving a knowledgeable team and using structured techniques like timelines or the “5 Whys” improves accuracy.

What is the difference between a root cause analysis and an incident report?

An incident report describes the immediate facts of an accident, while an RCA digs deeper to identify underlying causes. RCA accident report focuses on prevention by uncovering root causes, whereas an incident report captures details for documentation.

What is the simplest method of root cause analysis?

The simplest method is the “5 Whys,” which involves asking “WHY” repeatedly to trace a problem back to its origin. Another way is to use the fishbone RCA template to discover all the causes contributing to the incident or symptoms. This straightforward approach can reveal root causes without extensive resources.