HAZOP Procedure
A HAZOP procedure is an examination of an existing or planned operation (work) procedure to identify hazards and causes for operational problems, quality problems, and delays.
- Can be applied to all sequences of operations
- Focus on both human errors and failures of technical systems
- Best suited for detailed assessments, but can also be used for coarse preliminary assessments
- Flexible approach with respect to use of guide-words
HAZOP Procedure
Breakdown of operation (work) procedure to suitable steps
- Define intention of each step
- Establish boundary conditions else as conventional Process HAZOP
- Apply guide-words to intention and boundary conditions for each step.
HAZOP Guidewords:
| Guideword | Meaning |
| No (not, none) | None of the design intent is achieved |
| More (more of, higher) | Quantitative increase in a parameter |
| Less (lessof, lower) | Quantitative decrease in a parameter |
| As well as (more than) | An additional activity occurs |
| Part of | Only some of the design intention is achieved |
| Reverse | Logical opposite of the design intention occurs |
| Other than (other) | Complete substitution – another activity takes place |
Alternative Guidewords:
| Guideword | Meaning |
| Unclear | Procedure written in confusing and ambiguous fashion |
| Step in wrong place | Procedure will lead to actions out of correct sequence or recovery failure |
| Wrong action | Procedure action specified is incorrect |
| Incorrect information | Information being checked prior to action is incorrectly specified |
| Step omitted | Missing step, or steps too large, requiring too much of the operator |
| Step unsuccessful | Step likely to be unsuccessful due to demands on operator |
| Interference effects from others | Procedure-following performance likely to be affected by other personnel carrying out simultaneous tasks (usually when co-located) |
Alternative Guidewords/Deviation:
| Guideword | Meaning |
| Time | Too early, too late |
| Sequence | Wrong sequence, omissions, wrong action |
| Procedure | Not available, not applicable, not followed |
| Measurement | Instrument failure, observation error |
| Organization | Unclear responsibilities, not fitted for purpos |
| Communication | Failed equipment, insufficient/incorrect information |
| Personnel | Lack of competence, too few, too many |
| Position | Wrong position, movement exceeding tolerences |
| Power | Complete loss, partly lost |
| Weather | Above limitations – causing delayed operation |
HAZOP Reporting:
A typical HAZOP report consists of:
Summary
- Introduction
- System definition and delimitation
- Documents (on which the analysis is based)
- Methodology
- Team members
- HAZOP results
– Reporting principles
– Classification of recordings
– Main results
HAZOP Review:
Review meetings should be arranged to monitor completion of agreed actions that have been recorded. The review meeting should involve the whole HAZOP team. A summary of actions should be noted and classified as:
- Action is complete
- Action is in progress
- Action is incomplete, awaiting further information
HAZOP Results:
What results to expect?
- Improvement of system or operations
- Reduced risk and better contingency
- More efficient operations
- Improvement of procedures
- Logical order
- Completeness
- General awareness among involved parties
- Team building
The purpose of this is to investigate how the system or plant deviates from the design intent and create risks for personnel and equipment and operability problems. HAZOP studies have been used with great success within chemical and the petroleum industry to obtain safer, more efficient and more reliable plants.