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Team Based Studies

EPCONSULT is experienced in providing support to designers and constructers by facilitating team-based studies such as Process Hazard Analysis (which may employ a wide range of different techniques such as Hazard and Operability (HAZOP) studies, Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA) and What-If studies), Hazard Identification (HAZID), Environmental Issues Identification (ENVID), Technical Review, Safety Integrity Level (SIL) Assessment, Root Cause Analysis, Layer of Protection Analysis (LOPA) etc. We can provide a team leader (chairman) and scribe (secretary) for any team-based study, or even skilled discipline engineers to serve on the study team. Some of these studies are described in more detail below.

hazard identification studies

Process Hazard Analyses

Process Hazard Analysis (PHA) is an umbrella term for a number of different study techniques, notably

  • What If Analysis
  • Checklist Analysis
  • What If/Checklist Analysis
  • Hazard and Operability (HAZOP) Study
  • Failure Modes and Effects Analysis (FMEA)
  • Fault Tree Analysis (FTA)

What If, Checklist and HAZOP are normally conducted in a team-setting. FMEA and FTA may be conducted by a team, but are more commonly conducted by an individual analyst.

Hazard Identification (HAZID) Studies

The primary purpose of a Hazard Identification (HAZID) Study is to identify the hazardous scenarios to be investigated in a subsequent risk assessment. Usually, a HAZID is conducted in a team setting. Depending on the scope, the HAZID may include a qualitative assessment of the hazards, and recommendations may be made for additional safeguards. Hazards that cannot be adequately assessed in the meeting will be referred for subsequent, more detailed investigation by another method.

An Environmental Issues Identification (ENVID) Study is conducted like a HAZID but with the aim of identifying environmental issues.

Safety Integrity Level (SIL) Assessment

SIL assessment is a risk based approach to identify the required safety integrity levels (SIL) for safety instrumented functions (SIFs) in accordance with IEC 61508 / 61511 or ANSI/ISA S84.01.

The SIL assessment is performed by a multidisciplinary team led by a SIL Facilitator. Determination of the SIL of a SIF can be achieved using different qualitative and quantitative approaches.

  • Risk Graphs – qualitative method, proposed in IEC 61508
  • Layers of protection analysis (LOPA) – alternative qualitative method, widely used in the process industry
  • Fault tree analysis (FTA) / Event tree analysis (ETA) – quantitative methods

Generally a combination of the methods is employed. For example, performing an initial qualitative assessment for all safety functions ("screening process") and performing a detailed quantitative assessment for the higher criticality or less well understood functions.

The outcome of the SIL assessment is followed by a SIL verification study, where the design of the safety instrumented system (SIS) is verified.

SIL assessment workshops may be conducted by a project team with facilitation by EPCONSULT and subsequent SIL verification also by EPCONSULT.

Root Cause Analysis

Root cause analysis is a process for investigating incidents to find their causes and prevent them from happening again. EPCONSULT uses the methodology known as SOURCE, developed by the US nuclear industry, which is a four-step process:

  • Data collection and preservation
  • Causal factor charting
  • Root cause identification
  • Recommendation generation and implementation

Root cause analysis may be conducted by a client team with facilitation by EPCONSULT.

FMECA and FTA (Fault Tree Analysis) are used to perform SIL verification.

Layer of Protection Analysis (LOPA)

Layer of Protection Analysis is a simplified form of quantitative risk assessment. In a typical process plant, various protection layers are in place to lower the frequency of undesired consequences: the process design (including inherently safer concepts); the basic process control system; safety instrumented systems; passive devices (such as dikes and blast walls); active devices (such as relief valves); human intervention; etc.

LOPA aims to answer the questions: How many protection layers are needed? How much risk reduction should each layer provide?

In LOPA, the individual protection layers proposed or provided are analyzed for their effectiveness. The combined effects of the protection layers are then compared against risk tolerance criteria. LOPA is not a hazard identification technique and scenarios for investigation must be identified by another method.

LOPA can be applied at any stage in the life cycle. At the earliest stages, it can be used to compare alternative concepts to determine which is inherently safer. In detail design or when modifications are made, LOPA can be used to complement HAZOP and other forms of Process Hazard Analysis.

If a safety instrumented function (SIF) is needed, LOPA can be used to determine the required Safety Integrity Level (SIL) in accordance with international standards IEC 61508 and IEC 61511 and US standard ISA S84.01.

LOPA can be used to identify safety critical equipment (e.g. ISA S91.01) and operator actions and responses that are critical to safety.

LOPA can be applied in a team-setting, with a facilitator provided by EPCONSULT. Alternatively, EPCONSULT can conduct LOPA as an external study, in a similar manner to a QRA.

Delivery of Training Courses

Safety Integrity Level (SIL) of Safety Instrumented Systems: The course initially addresses methods of reviewing process systems and plant to establish existing levels of SIL based on IEC 61508 / 61511. It then trains attendees in chairing a SIL Review and it covers methods of enhancing SIL level to achieve desired target availability followed by robust SIL Verification to demonstrate SIL level. Application of the techniques FMECA, LOPA and FTA is part of the course.

Please contact us to request further details of our services in facilitation of team-based studies.


 
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