Risk Assessment Methods Compared: HAZOP, HAZID, FMEA, SWIFT, and WRAC

If you’re building a risk management program for a mining, construction, or energy operation, you’ll need to choose from several established risk assessment methods. Each has its strengths. None is perfect for every situation.

This guide compares five of the most common methods — HAZOP, HAZID, FMEA, SWIFT, and WRAC — so you can match the right tool to the right job.

Quick Overview

Before diving in, here’s the 30-second summary:

• HAZID — Broad hazard identification. Cast the wide net first.
• HAZOP — Deep process analysis. Systematic deviation study for process plants.
• FMEA — Equipment focus. How can components fail and what happens?
• SWIFT — Flexible and fast. Structured brainstorming for any system.
• WRAC — Workplace-level. Task-based risk assessment common in Australian mining.

Now let’s look at each in detail.

HAZID: Hazard Identification Study

Purpose

Identify hazards across a broad scope — typically an entire project, facility, or operation. HAZID is usually the first step in a risk program, before more detailed methods like HAZOP or FMEA.

How It Works

A facilitated workshop uses checklists and prompts covering categories like:

• Natural hazards (weather, seismic, flood)
• Process hazards (fire, explosion, toxic release)
• Mechanical/structural hazards
• Human factors
• Environmental impacts
• External threats (security, third parties)

The team systematically works through each category, identifying hazards relevant to the operation.

When to Use It

• Early project stages — feasibility, concept, front-end design
• New operations — before detailed engineering is available
• Periodic reviews — has anything been missed in the existing program?
• When you need a comprehensive hazard inventory as a starting point

Strengths

• Broad coverage — catches hazards other methods might miss
• Relatively fast compared to HAZOP
• Doesn’t require detailed design information
• Good for setting the agenda for deeper studies

Limitations

• Less rigorous than HAZOP or FMEA for detailed analysis
• Quality depends heavily on the checklist and facilitator
• Doesn’t quantify risk in detail
• Not a substitute for detailed process or equipment analysis

HAZOP: Hazard and Operability Study

Purpose

Systematically examine a process system to identify deviations from design intent that could lead to hazards or operability problems.

How It Works

The process is divided into nodes (sections). For each node, guide words (No, More, Less, Reverse, Other Than, etc.) are applied to process parameters (flow, temperature, pressure, level, composition) to generate deviations.

Each deviation is examined for causes, consequences, existing safeguards, and the need for additional actions.

When to Use It

• Process plants — chemical, petrochemical, oil & gas, water treatment
• Detailed design review — when P&IDs and operating procedures exist
• Management of change — assessing modifications to existing processes
• When regulations require it (common in process safety jurisdictions)

Strengths

• Extremely thorough for process systems
• Guide word approach forces consideration of non-obvious deviations
• Well-established, globally recognised methodology
• Produces detailed, actionable records

Limitations

• Very time-intensive — complex plants can take weeks
• Requires trained facilitation and a multidisciplinary team
• Needs detailed design documentation (P&IDs, operating procedures)
• Less effective for mechanical failures or workplace-level risks

FMEA: Failure Mode and Effects Analysis

Purpose

Identify how components or process steps can fail, what the effects would be, and prioritise corrective actions based on risk.

How It Works

For each component (or process step):

1. List possible failure modes
2. Determine the effect of each failure
3. Score Severity, Occurrence (likelihood), and Detection (how easily spotted)
4. Calculate Risk Priority Number (RPN = S × O × D)
5. Assign corrective actions to high-RPN items

When to Use It

• Equipment and machinery assessment — mobile plant, fixed plant, vehicles
• Maintenance planning — critical failure modes drive inspection schedules
• Product/system design — manufacturing, engineering
• When you need quantitative prioritisation of failure modes

Strengths

• Systematic coverage of every component
• RPN provides quantitative ranking for resource allocation
• Directly links to maintenance and inspection programs
• Relatively straightforward to facilitate

Limitations

• RPN scoring can be misleading (different combinations produce the same number)
• Focuses on single-point failures, not complex interactions
• Doesn’t capture process deviations well
• Can produce very lengthy documents for complex systems

SWIFT: Structured What-If Technique

Purpose

A flexible, efficient risk assessment method that combines structured brainstorming with checklists. Sits between HAZID (broad but shallow) and HAZOP (narrow but deep).

How It Works

A facilitated workshop uses “What if…?” questions combined with checklists to systematically explore risks. The facilitator guides the team through scenarios:

• “What if the pump fails during transfer?”
• “What if the operator misreads the gauge?”
• “What if we have a simultaneous failure of backup systems?”

Each scenario is assessed for likelihood, consequence, existing controls, and additional actions needed.

When to Use It

• Any system or operation — SWIFT is highly adaptable
• When HAZOP is too time-intensive for the scope
• Operational reviews — assessing existing operations, not just design
• Smaller teams or shorter timeframes
• When you need something more rigorous than HAZID but faster than HAZOP

Strengths

• Fast and flexible — typically 2-3x faster than HAZOP for equivalent scope
• Works for process, equipment, and operational risks
• Less dependent on detailed design documents
• Encourages creative thinking about scenarios
• Good for operations teams, not just engineering

Limitations

• Quality depends heavily on the facilitator’s experience and preparation
• Less systematic than HAZOP — possible to miss deviations
• Not always accepted as a HAZOP substitute by regulators
• Checklist quality drives output quality

WRAC: Workplace Risk Assessment and Control

Purpose

Assess risks associated with specific workplace tasks or activities. WRAC is widely used in Australian mining and is mandated or recommended by several state mining regulators.

How It Works

1. Break work into tasks or activities
2. For each task, identify hazards present
3. Assess the risk (likelihood × consequence) with existing controls
4. Determine if existing controls are adequate
5. If not, identify additional controls using the hierarchy of controls
6. Reassess the residual risk with additional controls in place

WRAC typically uses a risk matrix specific to the organisation or site.

When to Use It

• Task-based risk assessment — specific jobs, procedures, work instructions
• Mining operations — particularly in Australia
• Frontline worker involvement — WRAC is designed for workers assessing their own tasks
• Pre-job safety assessments — before starting non-routine work
• When you need practical, task-level risk assessment rather than system-level analysis

Strengths

• Practical and accessible — frontline workers can participate meaningfully
• Directly applicable to daily work activities
• Aligns with hierarchy of controls
• Good for contractor and workforce engagement in risk management
• Simple enough for high-frequency use

Limitations

• Task-focused — doesn’t capture system-level or process interactions
• Risk matrix scoring can oversimplify complex risks
• Not suitable for detailed process or equipment analysis
• Quality varies widely depending on workforce engagement

Choosing the Right Method

Here’s a decision framework:

What are you assessing?

• A process plant → HAZOP (or SWIFT for faster analysis)
• Equipment/machinery → FMEA
• A workplace task → WRAC
• A whole operation (first pass) → HAZID
• Any system, flexibly → SWIFT

What stage are you at?

• Early project/concept → HAZID
• Detailed design → HAZOP or FMEA
• Operational → SWIFT, WRAC, or FMEA (for maintenance planning)
• Management of change → HAZOP or SWIFT

How much time do you have?

• Limited → SWIFT or WRAC
• Sufficient for thoroughness → HAZOP or FMEA

What does the regulator expect?

• Check your jurisdiction. Some regulators mandate specific methods for specific situations.

Using Multiple Methods Together

Most mature risk programs use several methods in combination:

1. HAZID first — cast the wide net, identify all hazard categories
2. HAZOP for process risks — deep dive into process safety
3. FMEA for equipment risks — drive maintenance and inspection
4. WRAC for task-level risks — engage the workforce in daily risk management
5. Bowtie analysis for critical risks — visualise barriers and monitor control health

The key is connecting the outputs. If your HAZOP identifies a risk, your FMEA flags related equipment failures, and your WRAC covers the daily task — those all need to feed into the same risk picture.

Bringing It All Together

The real challenge isn’t running the workshops — it’s making the outputs useful. Assessment results need to feed into:

• Risk registers that link risks to controls
• Action tracking that ensures corrective actions get completed
• Control monitoring that flags when barriers degrade
• Dashboards that show the current state of risk

RiskSight includes guided templates for all five methods — HAZOP, HAZID, FMEA, SWIFT, and WRAC. Outputs feed directly into linked risk registers with control tracking and action management. No more workshop reports gathering dust in a shared drive.

Start your free trial and run your first risk assessment today.