The Hazard and Operability Study (HAZOP) in clinical settings

Summary

While traditional methods such as Failure Mode and Effects Analysis (FMEA) are well-established, they often reach their limits in clinical practice. This is due in particular to the subjectivity of fault identification.

I would like to propose the Hazard and Operability Study (HAZOP) as a complementary risk analysis method. HAZOP offers a structured, systematic approach to risk identification and assessment, particularly suited to analysing process risks and human factors. Unlike FMEA, HAZOP uses guide words (e.g. NO, MORE, LATE, LESS, OTHER THAN) to explicitly identify and analyse potential deviations from tasks and procedures. 

Content

A systematic approach to identifying and assessing clinical risks

Despite the implementation of risk management systems, practice often falls short of expectations. This is due, among other factors, to the complexity of clinical processes, the dynamics of the work environment, and interprofessional interfaces, which make a holistic risk assessment difficult. Although traditional methods are widely used, they reach their limits in clinical practice:

• Subjectivity: When using traditional methods such as FMEA, which rely on the team’s spontaneous fault detection and experience, critical risks are easily overlooked as they are not recognised as ‘failure modes’.
• Monocausality: Traditional failure-mode-based approaches lead to a monocausal derivation of causes and effects.
• Human factors as ‘operator error’: Human errors are easily classified as ‘user problems’ without questioning the systemic causes (e.g. time pressure, unclear responsibilities, inadequate communication).

Against this background, I propose the Hazard and Operability Study (HAZOP) as a complementary risk analysis method. The HAZOP method was originally developed in the aviation industry and has established itself there as the gold standard for analysing risks in highly complex, safety-critical environments.

HAZOP enables the approach required by ISO 31000 as a structured, step-by-step approach:

1. Risk identification
2. Risk analysis
3. Risk evaluation

Risk identification using guide words

The method uses guide words as a heuristic to systematically identify potential process deviations as a starting point for the risk analysis. These guide words are adapted to clinical reality and enable a comprehensive risk analysis:

• Guide Word: Possible deviation.
• No: Failure to perform a task.
• More: Excessive performance of a task.
• Less: Inconsistent performance of a task.
• Late: Delayed performance of a task.
• Other than: Incorrect execution of a task.

Using guide words as a starting point for risk identification also helps to involve those with little experience in risk management in the process. A list of guide words can and should be adapted to the specific requirements of the specialist department.

Practical application: Example 'documentation of vital signs'

• Task: Recording and documenting vital signs in the intensive care unit.
• Guide word: Possible deviation
• No: Blood pressure is forgotten.
• Late: Documentation is delayed, delaying further diagnosis.
• Less: Not all vital signs are measured.
• Other than: A mix-up of patients in the documentation.

Risk analysis

The identified risks can be assessed using a two-dimensional risk matrix, like in other risk tools:

• Probability of occurrence (scale: ‘almost impossible’ to ‘almost certain’).
• Impact (scale: ‘no health consequences’ to ‘life-threatening consequences’).

This commonly used and well-known assessment method enables measures to be prioritised and helps hospitals to proceed in a resource-efficient way.

Risk evaluation and identification of measures

Preventive and corrective measures are developed during interprofessional workshops, in which representatives from all relevant professional groups (doctors, nursing staff, administration, IT) work together to evaluate risks and propose solutions.

Typical measures include:

• Process optimisations (e.g. standardisation of documentation procedures).
• Training to raise awareness of human factors.
• Technical adjustments (e.g. introduction of digital checklists).
• Clarification of responsibilities (e.g. through clear SOPs).

Discussion

The HAZOP method offers several key advantages that are particularly relevant to clinical patient safety:

• The use of guide words enables risks that are often overlooked to be systematically identified. This reduces subjectivity in error detection and enables more objective prioritisation of measures.
• The method allows for the analysis of human and organisational factors. This enables a holistic view of incident causes and supports hospitals in developing systemic solutions.
• HAZOP can be seamlessly integrated into the SEIPS 2.0 approach, which enables a coherent risk assessment that accounts for all relevant factors.
• The approach promotes collaboration among professionals from different disciplines. This strengthens the learning culture and helps to close governance gaps.
• Thanks to the structured approach and the use of guide words, risk analysis can be carried out more quickly and efficiently.

Conclusion

The HAZOP method, with its guide words, is a proven, systematic and evidence-based tool for improving clinical patient safety. It enables a comprehensive risk analysis that takes into account technical, procedural and human factors.

Do you use the HAZOP method? We would love to hear from you if you're using HAZOP in a clinical setting so we can share real-life examples of its use. Email us at [email protected] or comment below (you need to be signed into the hub; sign up here, it is free and easy to do).

About the Author

Stefan is a consultant focused on systems modelling, patient safety, clinical process design, and socio-technical work systems in healthcare. This pilot study reflects an interest in how structured models can support more transparent and reusable preparation for clinical governance discussions.