Process Hazard Analysis Related Studies

HAZOP, HAZID, LOPA, Bow-Tie & Safety Instrumented Systems Studies

Process Hazard Analysis

In the United States, the use of Process Hazard Analysis (PHA) is mandated by the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA). The Process Safety Management standard mandates the identification of risks involved in the design, operation, and modification of processes that handle highly hazardous chemicals.

IFO Group consultants can provide a full range of PHA services to include HAZOP studies, LOPA studies, HAZID studies, FMEA, Fault Tree Analysis, HAZOP studies, What If / checklist studies, and Bow-Tie Assessments.   If you need the following, our IFO Group PHA Experts can support you:

  • An experienced facilitator to lead an initial or revalidation PHA to meet PSM (Process Safety Management) regulatory or corporate requirements in the United States or elsewhere
  • A facilitator for a PHA ranging from a half day to weeks or months in duration
  • Support updating an out-of-date Process Hazard Analysis (PHA) that doesn’t reflect recent changes to your facility or your process
  • To evaluate the hazards presented by differing project options or approaches and select a concept that is the best fit for a cost, risk and operational perspective

We use a variety of approaches to support our clients in their execution of Process Hazard Analysis (PHA) and upon request, can utilize the following software packages to aid process safety risk management decision making:

  • DNV GL – Phast
  • FMEA-Pro
  • LOPAWorks 3
  • PHA-Pro
  • PHAWorks 5
  • Safeti
  • SVA-Pro

For more details, click on the “Request a Consultation” button on the right side of this page, call us, or send us an email and we’ll be happy to provide you with a free consultation to discuss your needs!


An IFO Group facilitator works with your designated team of people to conduct a HAZOP study.  Our facilitator is responsible for guiding your team’s brainstorming and discussion of causes and consequences of possible incident scenarios.  Then the team is led through an open forum to formulate recommendations for appropriate corrective actions.  If desired, we can also provide a study scribe to expedite and streamline the HAZOP study documentation.

LOPA (Layer of Protection Analysis) Studies

A Layer of Protection Analysis (LOPA) Study is used in conjunction with other PHA techniques, especially HAZOP, to determine if there are sufficient layers of protection against an identified high-risk incident or scenario.  It can also be used to ensure additional safeguards are in place to reduce risk to a tolerable level.  LOPA studies are also commonly used to identify Safety Integrity Level (SIL) values required for Safety Instrumented Functions (SIF) in Safety Instrumented Systems (SIS) to comply with the IEC 61511 / ISA S84 standards.

HAZID (Hazard Identification) Studies

A Hazard Identification Study (HAZID) is a high-level, systematic study of process hazards that uses checklists of hazards to identify materials, systems, processes, and facility characteristics that could produce undesirable consequences through the occurrence of an incident.   HAZID studies are frequently used for the early identification and assessment of hazards to provide critical input for project decisions at a time when design changes would have minimum cost penalties.   The HAZID Study is a crucial part of a project’s risk assessment and is typically a key milestone to complete in the Conceptual and Front-End Engineering Design (FEED) phases of capital projects.  It is conducted by a multi-disciplinary team using a structured, brainstorming approach, guided by checklists and guide words.  For each identified hazard, the team discusses potential causes, the consequences of those causes, the safeguards and mitigation measures present within the design to address those hazards, and any necessary recommendations to reduce the risk of the scenario.

Bow Tie Assessments (BTA)

Bow Tie Assessments (BTA) are a systematic method for graphically analyzing and demonstrating causal relationships in plausible high-risk scenarios involving a given hazard.  Control measures are then documented to demonstrate current risk mitigations.   Finally, the failure scenarios or conditions aka the ‘escalation factors’ for the control measures are identified.  Bow Tie Analysis can also be effectively used in conjunction with appropriate process safety management systems to demonstrate that major hazards for an organization are being managed to ALARP (As Low as Reasonably Practicable).

What If? Studies

The What-If? Study is a high-level systematic method for examining the responses of process systems to equipment failures, human errors, and abnormal process conditions. This technique requires participation by team members who know and understand the basic hazards associated with the process and its operation. The facilitator assists the client’s team with developing “what-if” questions about the process (e.g., “What if the pressure relief valve fails to open as expected?”). By answering these questions, the team identifies potential hazards and suggests ways to improve safety.  The results of a What-If Analysis are documented by listing the specific questions, responses, and recommendations generated by the team.  One of the strengths of this method is that it can be applied to any system at any stage of its design, development, or operation.

Failure Mode and Effects Analysis (FMEA)

The failure mode and effects analysis (FMEA) technique is a methodical study of system component failures. All failure modes for each component in a system are identified and the effect of each component failure on the overall system is evaluated.  This technique is most commonly used for processes that do not involve reactive chemistry but can be effectively used for interlock and emergency shutdown (ESD) systems.


Our consultants can team with your staff to provide a full range of PHA study related services by:

  • Assisting with the development of PHA corrective actions and implementation strategies.
  • Facilitating and scribing PHA studies.
  • Facilitating studies with the assistance of client scribes.
  • HAZOP (Hazard and Operability) Studies
  • Revalidating and updating existing PHA studies.
  • Training and coaching new client facilitators during studies.

A Hazard and Operability Study (HAZOP) is a structured and systematic PHA of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel, equipment, the environment or efficient operations.  HAZOP is a qualitative technique based on guide words and is conducted by a multi-disciplinary team.

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