RA Technique

IDENTIFICATION OF INDUSTRIAL HAZARDS WITH RISK ASSESSMENT TECHNIQUE

There are many risk assessment technique available in the industry which can be used to identify industrial hazards. Below outlined the various techniques that can be used to identify hazards and provide a brief overview of their advantages and disadvantages.

It should always be remembered that any system or operation comprises:
people, procedures, equipment and an environment of operation

All these elements must be considered during hazards identification.

Risk Assessment Technique for Identification of Industrial Hazards

What-if analysis

Hazard and Operability Study (HAZOP)

Fault Tree Analysis

Event Tree Analysis

Failure Mode and Effects Analysis

Job Safety Analysis

In this post, only the following techniques will be explained

HAZARD AND OPERABILITY STUDY (HAZOP)

HAZOP is a systematic and structured approach using parameter and deviation guidewords. The technique relies on a very detailed system description being available for study and usually involves breaking down the system into well defined subsystems and functional or process flows between subsystems. Each element of the system is then subjected to discussion within a multidisciplinary group of experts against the various combinations of the guidewords and deviations.

The group discussion is facilitated by a Chairman and the results of the discussion recorded by a Secretary together including any hazards identified when a particular guideword and deviation combination is discussed. Where a particular guideword and deviation combination does not produce any hazards, or is not though t credible, this should also be recorded to demonstrate completeness.

The guidewords and deviations must be prepared in advance by the HAZOP Chairman and may need to be tailored to the system or operation being studied.

In an aviation context, typical guidewords might include:

Detection

Co-ordination

Notification

Transmission

Clearance

Authorisation

Selection

Transcription

Supervision

Typical deviations might include:

Too soon / early

Too late

Too much

Too little

Too high

Too low

Missing

Twice / repeated

Out of sequence

Advantages of Hazard and Operability Study

Systematic and rigorous.

Involves interaction of views from multidisciplinary experts.

Can be applied to a wide range of types of system.

Creates a detailed and auditable record of the hazards identification process.

Disadvantages of Hazard and Operability Study

Requires a considerable amount of preparation.

Can rely heavily on the skills of the HAZOP Chairman

Can be time consuming and therefore expensive.

Can inhibit imaginative thinking and so certain kinds of hazards.

FAILURE MODE AND EFFECT ANALYSIS.

FMEA is a ‘bottom up’ technique that is used to consider ways in which the basic components of a system can fail to perform their design intent. This could either be at an equipment level or at a functional level. The technique relies on a detailed system description and considers the ways in which each sub-component of the system could fail to meet its design intent and what the consequences would be on the overall system. For each sub-component of a system an FMEA considers:

All the potential ways that the component could fail.

The effects that each of these failures would have on the system behaviour.

The possible causes of the various failure modes.

How the failures might be mitigated within the system or its environment.

Behaviours at the system level arising from the sub-component failures which have a safety consequence are thus identified as hazards. The system level at which the analysis is applied can vary and is determined by the level of detail of the system description used to support the analysis. Depending on the nature and complexity of the system, the analysis could be undertaken by an individual system expert or by a team of system experts acting in group session.

Advantages of FMEA

Systematic and rigorous.

Creates a detailed and auditable record of the hazards identification process.

Can be applied to a wide range of types of system.

Disadvantages of FMEA

Only really considers hazards arising from single point failure modes rather than combinations of failures.

Relies on people with detailed system knowledge.

Can be time consuming and expensive

WHAT IF

What If is developed as a simpler and more efficient alternative technique to HAZOP
Like HAZOP, What If involves a multidisciplinary team of experts under the facilitation of a Chairman. It is a facilitated brainstorming group activity but is typically carried out on a higher level system description , having fewer sub elements, than for HAZOP and with a reduced set of prompts.

Ahead of the group session the Chairman prepares a suitable list of prompts such as:

What if...?

Could someone...?

Has anyone ever...?

The Chairman uses the prompts to initiate discussion within the group.

Advantages of What If

Creates a detailed and auditable record of the hazards identification process.

Is less time consuming than other systematic techniques such as HAZOP.

Disadvantages of What If

Careful thought is required in preparation for the application of the technique.

Relies heavily on the expertise and experience of the team members.

Relies heavily on the skills of the Chairman