What are the Elements of Root Cause Failure Analysis and Failure Analysis Engineering?

Last Updated: May 2026

At Gilmore Engineers, we are trained failure analysis engineers: specialised technical professionals who investigate why materials, components, or systems fail, identifying the root cause to prevent future occurrences.

Root Cause Failure Analysis (RCFA) reduces downtime and improves safety in industries like oil and gas, manufacturing, and engineering. Combining physical failure analysis (laboratory investigation) with root cause analysis creates a complete understanding of what may occur or what did occur.

Here are some helpful definitions:

• Failure Analysis (FA): Identifies the immediate physical cause (e.g. fracture, corrosion, fatigue).
• Root Cause Analysis (RCA): Uncovers the underlying process, human or systemic failures (e.g. poor design, lack of training).
• RCFA: Combines both to prevent future issues, often used for high-impact or recurring failures. 

In this blog, we’ll discuss common steps taken to complete these investigations.

 

What Main Steps are Taken in RCFA?

1. Define and Collect: Form a team, gather evidence (damaged parts, data, interviews), and define the failure.

2. Analyse: Use methods (described below) to determine the mechanism and root cause.

3. Implement Solutions: Develop corrective actions that break the chain of events leading to the failure. 

 

 

What Methods are used in RCFA?

5 Whys: Repeatedly asking ‘why’ to dig deeper

The 5 Whys is a foundational Root Cause Analysis (RCA) technique. This iterative, interrogative method explores the cause-and-effect relationships underlying a specific problem by repeating the question ‘Why?’, typically five times, to move beyond superficial symptoms and uncover the root cause.

1. Assemble a Team: Gather people with firsthand knowledge of the process or failure (operators, maintenance technicians, engineers).
2. Define the Problem: Create a clear, specific, and data-driven problem statement.
3. Ask the First ‘Why’: Determine why the problem occurred. The answer must be based on evidence (data, physical inspection), not speculation.
4. Iterate ‘Why’ Four More Times: For each answer, ask again. Continue until the root cause (usually a breakdown in a process, policy, or system) is identified.
5. Implement Countermeasures: Develop actions to prevent the root cause from happening again. These should target the system rather than assigning blame.
6. Monitor Results: Verify that the corrective actions solved the problem.

 

Fishbone (Ishikawa) Diagram: Categorising potential causes (people, process, equipment)

A Fishbone (Ishikawa) Diagram is a structured, visual RCFA tool designed to help engineers identify, categorise, and address the underlying causes of a problem rather than merely treating its symptoms. It organises potential causes into major branches (often the 6Ms) to foster brainstorming and systematic investigation of complex failures.

• Fish Head (The Effect): The specific, clearly defined problem statement or failure.
• The Spine: A horizontal line leading to the problem statement.
• Bones Categories/Causes): Branching lines representing potential causes/’6Ms.
  • Manpower/People: Skills, training, fatigue, or human error.
  • Machine/Equipment: Tooling, maintenance, calibration, or software.
  • Method/Process: Procedures, operational, or design flaws.
  • Material: Raw materials, components, or supplier quality.
  • Measurement: Data accuracy, inspection, or gauge variation.
  • Mother Nature/Environment: Temperature, humidity, or workplace layout.

 

Fault Tree Analysis: A visual mapping of cause-and-effect chains

Fault Tree Analysis (FTA) is a deductive, top-down engineering tool used in RCFA to identify the underlying causes of a specific, undesired system failure. It breaks down complex failures into basic events using logic gates to visualise pathways and determine the root cause, supporting proactive improvements. Steps: define the issue, identify potential causes, construct the tree, and determine the root causes.

• Top Event: The undesired failure incident defined at the start.
• Logic Gates: AND gates show that all events must occur; OR gates show that any of the events can cause the failure.
• Basic Events: The lowest level causes (e.g., component failure, human error) that require no further decomposition.

 

FMEA (Failure Mode and Effects Analysis): Identifying potential failures before they happen

FMEA is a proactive, structured method used by engineers to identify potential product or process failures, their effects, and root causes before they occur, typically during design or manufacturing planning. It ranks risks using a Risk Priority Number (RPN) based on Severity, Occurrence, and Detection, enabling teams to mitigate high-risk issues early.

1. Identify Failures: Brainstorm all potential failure modes.
2. Determine Effects: Rate the severity of each failure.
3. Identify Causes: Trace each failure back to its underlying root cause.
4. Assign Ratings: Rate the occurrence (probability) and detection (probability of finding it).
5. Calculate RPN: Severity x Occurrence x Detection.
6. Develop Actions: Implement controls to minimise failure.

 

Contact Us

At Gilmore Engineers we have decades of specialised experience in Root Cause Failure Analysis (RCFA) and producing forensic engineer reports for courts and insurance companies. We’re recognised as a leading Australian consultancy specialising in investigating machinery failures, workplace injuries, and accident reconstruction.

Contact us today.

 

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