What is Root Cause Analysis? Methods, Process, and When to Use It

Why root cause analysis matters

Repeat failures are expensive. In heavy industry, a single unplanned shutdown can cost hundreds of thousands of dollars in lost production, emergency maintenance, and safety exposure. When organisations treat each failure in isolation without understanding why it occurred, they fund the same problem repeatedly.

The business case for RCA is straightforward:

• Repeat failures consume maintenance budgets without improving reliability
• Safety incidents that share a common cause will recur until that cause is eliminated
• Near misses that go uninvestigated are future incidents that have not yet been costed
• Regulatory and insurance frameworks increasingly require documented investigation of significant events

Common RCA methods compared

Several structured methods exist for root cause investigation. Each has appropriate applications depending on incident complexity, available evidence, and the depth of analysis required.

For most asset management and reliability engineering applications, Apollo RCA provides the strongest combination of rigour, evidence discipline, and practical usability in a workshop setting.

The Apollo Root Cause Analysis methodology

Apollo RCA is built on a single principle: every cause on the chart must be supported by evidence. If there is no evidence for a cause, it does not appear on the chart. This separates Apollo RCA from methods that rely on team consensus or the facilitator’s assumptions.

The methodology works by constructing a cause-and-effect chart that starts with the defined problem and works backward through all contributing causes. At each node, the investigator asks: what caused this? Two conditions must be met before a cause is accepted: it must be necessary (the effect would not have occurred without it) and it must be supported by verifiable evidence.

This approach produces several advantages:

• Multiple cause paths are captured, reflecting the real complexity of failures rather than a single linear chain
• The completed chart is transparent and auditable — every finding can be traced back to its evidence
• Corrective actions are mapped directly to specific causes, making recommendations targeted and defensible
• The chart is a communication tool, allowing leadership, engineers, and frontline staff to understand the investigation findings without needing to read a lengthy report

Holistic Asset Management holds certification to train and facilitate Apollo RCA. Our engineers are also accredited distributors of RC Pro, the software platform used for Apollo RCA charting.

For a detailed explanation of the Apollo methodology, see our article on what Apollo Root Cause Analysis is.

When should you conduct an RCA?

Not every failure warrants a full formal investigation. The decision to conduct an RCA should be triggered by the consequence or potential consequence of the event, and by whether the event is likely to recur without intervention.

Common triggers include:

• Safety incidents: Any lost-time injury, recordable incident, or high-potential near miss. Regulatory requirements often mandate formal investigation.
• Repeat failures: Equipment or systems that fail repeatedly, even where each individual event is low-cost. Recurrence is evidence that prior corrective actions did not address root cause.
• High-cost events: Unplanned shutdowns, catastrophic equipment failures, or production losses above a defined threshold.
• Near misses: Events that had the potential for serious consequence. Near misses are leading indicators; the same causes will produce an actual incident if not resolved.
• Process failures: Quality escapes, environmental incidents, or contract non-conformances that share causes with operational failures.

The RCA process step by step

A well-run RCA follows a consistent sequence regardless of the specific methodology used:

1. Define the problem: State the event with precision — what happened, when, where, and what the consequence was. A vague problem statement leads to unfocused investigation.
2. Gather evidence: Collect physical evidence, operational data, maintenance records, witness accounts, and procedural documentation before it is lost or altered. Time is critical in the immediate aftermath of an event.
3. Build the cause-and-effect chart: Work backward from the problem through all contributing causes. In Apollo RCA, each cause is validated against available evidence.
4. Identify root causes: Root causes are causes that, if eliminated, would prevent recurrence. They are the deepest points on the chart where intervention is both feasible and effective.
5. Develop corrective actions: For each root cause, define a specific corrective action with an accountable owner and a completion date. Corrective actions should be tested: will this action, if implemented, prevent this cause from occurring again?
6. Report and close: Document findings in a format appropriate for the audience. Track corrective action implementation to completion. Follow up to confirm effectiveness.

What makes an effective RCA facilitator?

The quality of a root cause analysis depends heavily on the facilitator. An effective RCA facilitator brings three things: independence, structured process discipline, and evidence focus.

Independence is the most critical factor. A facilitator who is part of the team being investigated, or who has a stake in a particular outcome, will consciously or unconsciously steer the investigation toward a preferred conclusion. Maintaining facilitator independence is a core competency in Apollo RCA practice.

Structured process discipline keeps the investigation focused and prevents the group from jumping to solutions before causes are fully understood. An experienced facilitator manages the team dynamic, ensures all voices are heard, and holds the investigation to the evidence standard.

Evidence focus distinguishes a credible investigation from a post-hoc rationalisation. The facilitator’s role is to challenge assumptions and require evidence for every cause claimed. This is what separates an Apollo RCA chart from a brainstorming session.

Assembling the right investigation team is equally important. See our guidance on building cross-functional teams for Apollo RCA.

RCA training in Australia

Holistic Asset Management is an accredited Apollo RCA training provider and accredited distributor of RC Pro software. We deliver both open and in-house training programs, and provide independent facilitation for organisations investigating significant events.

Our engineers have facilitated RCA investigations across mining, oil and gas, manufacturing, rail, and utilities — covering equipment failures, safety incidents, and process non-conformances. We bring the same evidence-based discipline to every engagement regardless of industry or event type.

Training is available for reliability engineers, maintenance managers, safety professionals, and operational leaders who need to build in-house investigation capability. Facilitation services are available where an independent external investigator is required or preferred.

• Apollo RCA training programs — open enrolment and in-house delivery across Australia
• RCA facilitation services — independent investigation for significant events
• Contact us to discuss training needs or facilitation requirements