Method: Productivity improvement methods
Traditionally, safety in the design of factories heavily relied on industry regulations, the application of codes and checklists based on the experience and knowledge of company staff. Unfortunately, such an approach can only cope only to some extent.
Hazard and Operability Studies (HAZOPs) were developed as a technique to systematically and rigorously identify potential hazards and operability problems with new designs of both batch and continuous processes.
HAZOP study is well-proven structured team-based method for hazard identification at process design completion or for planned modifications. The technique makes detailed examination of the process and engineering intention of new or existing facilities to assess the hazard potential of operation outside the design intention, or malfunction of individual items of equipment and their consequential effects on the facility as a whole. A successful HAZOP is dependent on the competence of the people in the room to ensure all causes of undesirable plant conditions can be identified. HAZOP is based on a theory that assumes risk events are caused by deviations from design or operating intentions. Identification of such deviations is facilitated by using sets of “guide words” as a systematic list of deviation perspectives. This approach is a unique feature of the HAZOP methodology that helps stimulate the imagination of team members when exploring potential deviations.
As a risk assessment tool, HAZOP is often described as:-
- A brainstorming technique.
- A qualitative risk assessment tool.
An inductive risk assessment tool, meaning that it is a “bottom-up” risk identification approach, where success relies on the ability of subject matter experts (SMEs) to predict deviations based on past experiences and general subject matter expertise. In addition to its utility in Quality Risk Management, HAZOP is also commonly used in risk assessments for industrial and environmental health and safety applications.
When describing the HAZOP methodology, the following definitions are useful:-
Hazard:-Potential source of harm. Deviations from design or operational intent may constitute or produce a hazard. Hazards are the focus of HAZOP studies, and it should be noted that a single hazard could potentially lead to multiple forms of harm.
Harm:-Physical injury or damage to the health of people or damage to property or the environment. Harm is the consequence of a hazard occurring and may take many forms: patient or user safety, employee safety, business risks, regulatory risks, environmental risks, etc.
Risk:-Combination of probability of occurrence of harm and the severity of that harm. In a strict sense, “risk” is not always explicitly identified in HAZOP studies since the core methodology does not require identification (also referred to as rating) of the probability or severity of harm. However, risk assessment teams may choose to rate these factors in order to further quantify and prioritize risks if needed.
HAZOP is best suited for assessing hazards in facilities, equipment, and processes and is capable of assessing systems from multiple perspectives:-
- Physical and operational environments
- Operational and procedural controls
The below approach can help us determine a systematic decision process for devising HAZOP or the most suitable risk assessment and evaluation method.
Step 1: Perform a gross hazard analysis
Step 2:-Review results of the gross hazard analysis
Step 3:-Determine appropriate methodology for more detailed analyses
Identifying hazards is an important first step in assessing the risks associated with them. However, identifying hazards does not determine the actual risks or to what extent a hazard needs to be controlled or mitigated against. The risk assessment helps to target where you should invest time and resource to achieve the highest overall level of safety. HAZOP definitely helps towards a safe working place, but it should be considered just as one of the means to provide a safe and reliable environment. It should be used along with other risk assessment, evaluation and control techniques to work effectively in achieving the objective of safety in everything.