Process Hazard
Analysis (PHA)
Training by: Syed Hassan Sultan Date: 17 March 2016
PROCESS HAZARD
ANALYSIS (PHA)
TRAINING CONTENT:
Module 1: PHA in the context of PSM
Module 2: PHA Process Overview
Module 3: PHA Planning & Preparation
Module 4: PHA Execution-Hazard
Identification
Module 4a: Hazard & Operability Study
(HAZOP) Technique Overview
Running business implies taking
risks….
Module 1: PHA in the
context of PSM
Module 1: PHA in the
context of PSM
Operational risks cover a large portion of the entire risk portfolio that major corporations are facing on a day-to-day business
---Adopting an integrated approach to the Company Risk
Portfolio---Module 1: PHA in the
context of PSM
Process Hazard Analysis (PHA) is applied to understand risks involved in the design, operation, and modification of processes that handle hazardous materialsUnderstanding of risks plays a central role as it drives effective risk management activities
Module 1: PHA in the
context of PSM
The impact to company’s objectives varies depending on the risks
Module 1: PHA in the
context of PSM
PHA mainly focus on risks associated with handling of hazardous material with
Module 1: PHA in the
context of PSM
It’s necessary to recognize the final implications to the company
Module 2: PHA Process Overview
A “Hazard” is commonly considered as the “potential for…”
Module 2: PHA Process Overview
A “Hazard” is commonly considered as the “potential for…”
Module 2: PHA Process Overview
Every PHA implementation follows 3 phases
Module 2: PHA Process Overview
PHA Execution: Logical Steps
Key steps of the PHA execution depend on the defined scope and methodology to be applied. In general terms, three main logic steps can be identified for any PHA
Module 2: PHA Process Overview
There is not a uniform consensus across industries and standards on the terminology describing risk management process steps
---Example of terminology from different
standards---Module 2: PHA Process Overview
A Comprehensive PHA program encompasses a number of components which are interconnected to provide a
complete understanding of risks.
---Key relationship among different PHA components (Not
Exhaustive)---The Hazard Identification stage is one of the most important steps
Module 3: PHA Planning
and Preparation
Careful preparation lays the groundwork for a successful study
Module 4: PHA
Execution-Hazard Identification
Hazard identification is the first step in a systematic process which aims to improve the management of risk
Module 4: PHA
Execution-Hazard Identification
A number of techniques can be used in the hazard identification
---Common Hazard Identification
Methodologies---Module 4: PHA
Execution-Hazard Identification
Different techniques apply different logic to help identifying hazards
Module 4: PHA
Execution-Hazard Identification
Different techniques apply different logic to help identifying hazards
• What if / Checklist review can enter the logic at any point in the cause & effect relationship
• FMEA begins with looking at the cause (failed regulator) & works toward defining the consequence (vessel rupture)
• HAZOP begins with deviation (high pressure), determines the consequence (vessel rupture), and then identifies potential causes (failed regulator) of the deviation
Module 4: PHA
Execution-Hazard Identification
Potential Hazards:
---Five Hazard
Categories---Module 4a: Hazard and
Operability Study (HAZOP)
A HAZOP is a group technique used to identify hazards and operability issues arising from process deviations from plant design intent
The technique is used to identify
Hazards (ways the system can fail leading to human loss/injury, asset damage or environmental impact
Operability (ways in which the system can fail
to perform as required)
• The approach is formal and systematic using a structured question and answer procedure to identify deviations from the intent of the design. • The study is performed by a team of people
familiar with the system design and operation, working under the guidance of a leader who is experienced in the HAZOP method.
• The leader systematically applies a set of specific guideword-parameters combinations to evaluation deviations in terms
of causes, consequence, safeguards.
• The team evaluates whether existing safeguards are adequate to protect from the identified scenario; if not a recommendation for improvement is raised.
• A recorder makes a detailed tabulation of the team discussion.
Module 4a: Hazard and
Operability Study (HAZOP)
The team for a HAZOP is selected from the available staff who will need to be free of others duties for the period of the study
Module 4a: Hazard and
Operability Study (HAZOP)
Process deviations result from the
combination of guidewords to
Module 4a: Hazard and Operability Study (HAZOP)
HAZOP can also be applied to batch
processes, using Ad Hoc guidewords applied to “ACTION”
Guidewords Deviation
No Action not executed
More Of Too much of action
Less Of Too less of action
As well as Additional action executed although not required
Part Of Action partially executed
Other than Incorrect action
Before Action executed too early
After Action executed too late
Disordered Action executed in the wrong order / sequence
Module 4a: Hazard and
Operability Study (HAZOP)
Select line or vessel
Define node & design intention of node
Select parameter & guide word
Develop meaningful deviation
Identify all possible causes for the deviation
List safeguards & protection available Describe consequences if all safeguards fail
Evaluate need for risk control recommendation
Start here for each process line and vessel
Repeat for all guide words & parameters
Module 4a: Hazard and
Operability Study (HAZOP)
A number of criteria and approaches can be used by the HAZOP Leader to identify /select
the nodes. Here are the most frequent adopted:
• Process Flow Analysis: the leader follows the main flows from/to the different process equipment and lines
• Presence of Loops: the leader can follow process loops when selecting the sequence of the Nodes
• Complexity of Equipment: Node coincide with 1 single process equipment, including relevant inlet/outlet lines and relevant instrumentation.
• “Line by Line” Approach: assigning a Node to each of the main process line and equipment.
COMMUN ITY EMERGENCY RESPONSE PLANT EMERGENCY RESPONSE MITIGATION PREVENTION
Module 4a: Hazard and
Operability Study (HAZOP)
Part of the team discussion should include the layers of protection which already exist and the extent to which they are adequate
CONTROL & MONITORING
PROCESS
• The team members need a good
knowledge of the plant to explain accurately the protections already in place
• The extent to which these are
considered adequate depends on the size of the risk posed by the hazard
• The discussion should refer to the basic
process control system as well as any engineering controls or administrative procedures which are in place
Layers of Protection
Module 4a: Hazard and
Operability Study (HAZOP)
Examples of HAZOP Notes-How do you judge the quality?
Module 4a: Hazard and
Operability Study (HAZOP)
It’s important to clearly write recommendation so that they can be actionable
--- Examples of “Good Quality” of recommendations
---Module 4a: Hazard and
Operability Study (HAZOP)
---Inadequate Quality of HAZOP-Key
Factors---• Inadequate Study Time
• Inadequate Documentation • Inadequate Team Members • Incomplete Study
• Inadequate Team Guidance • Inadequate Facilities