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 We simplify compliance with IEC 61511 and ANSI/ISA 84.00.01-2004
by integrating the functional safety management requirements with
proven project management processes. SIS-TECH backs these work
processes with highly experienced personnel that address your safety,
environmental, asset protection, and business interruption risks and
achieve your reliability, operability, and maintainability goals.
With common values,
complementary strengths and a customer-focused approach, SIS-TECH
provides you with critical expertise that we have gained from executing
projects in similar chemical processes at other companies. There are
many different ways to achieve compliance with the standards - some
good and some bad. We can share with you our lessons learned and help
you avoid pitfalls that can affect your process performance.
Whether you need assistance with implementing
management systems, assessing process hazards, or
defining risk management strategy, SIS-TECH's distinct
approach yields more cost effective solutions.
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Call SIS-TECH
for assistance with any of the following:
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Management
System Policies and Procedures
Quality design is achieved
in an environment that fosters a safety and reliability-focused
workforce. All successful quality programs
have one thing in common: a documented management
system with defined metrics for monitoring and improving
performance. SIS-TECH can provide consultants to build
policies and procedures, to train your personnel,
and to implement a protective management system for
a specific site or for an entire company.
The SIS-TECH
approach fulfills the intent of the ANSI/ISA
84.00.01-2004 (IEC 61511 modified) for new facilities.
It also fulfills the documentation and procedural
requirements for existing facilities by including
a method for documenting that the systems in place
provide the required risk reduction, fulfilling the
"Grandfather Clause" requirements. We know
our work fulfills the intent of the standards because
we were there when the standards were developed, listening
to the concerns of the various parties and participating
in writing the clauses. We chair the committees and
help write the technical reports. We author papers
and books and teach training courses all over the
world. Our methodologies are proven-in-use.
SIS-TECH works with your personnel
to tailor a protective management system that meshes
with your existing project and risk management philosophy.
Each procedure includes the following:
- Scope.
- Applicability.
- Identification of
key skills and resources, including responsibilities.
- Work process including
key requirements.
- Expected documentation.
- Change management process.
- Audit process to evaluate
compliance to procedure.
The following policies and procedures
are generally established:
- Policy Concerning Risk
Criteria.
- Policy Concerning
the Management of Existing Safety Instrumented Systems.
- Hazard & Risk Analysis
Procedures with Software.
- Outlining
Use of Risk Criteria and Process Hazards Analysis
Methods.
- Identification of Safety
Instrumented Systems (SIS).
- Assignment of Safety
Integrity Levels (SIL).
- Process Engineering
and I&E Design Guidelines for Safety Instrumented
Systems.
- SIL Verification Procedure
with Software.
- Data Collection and
Analysis Process.
- Management of Change
Procedures.
A thorough Hazard and Risk Analysis (H&RA) is the first and most important step in the SIS lifecycle. The H&RA encompasses many different types
of risk analysis, such as process hazards analysis
(PHA), layers of protection analysis (LOPA), quantitative
risk assessment (QRA), and consequence modeling. SIS-TECH
works with your personnel to develop H&RA policies
and procedures and provides trained facilitators for
study execution. Once completed, our consultants can
review the H&RA results to define an overall risk
mitigation strategy that provides the necessary risk
reduction, while meeting the reliability, operability,
and maintainability requirements of the process unit.
To achieve a consistent, quality output
from the H&RA phase, you should consider the following:
- Development of a clear statement
of the risk criteria for various types of process
hazards.
- Documentation of policies
and procedures to assess and respond to identified
process risk.
- Identification of resources
required to execute these policies and procedures.
- Implementation of an audit
process to evaluate compliance to policies and procedures.
With so many analysis options, it can be difficult
to determine what methods are appropriate for various
types of risk. Many risk assessments employ high level,
qualitative techniques with worse case scenario assumptions,
leading to similarly conservative and costly design.
Assessing all risk by a quantitative technique is
generally not practical, because limited resources
are spent executing rigorous methods on potentially
low risk events. SIS-TECH works with your personnel
to develop an overall work process using your existing
process hazards analysis (PHA) methodologies to screen
risks for review using more rigorous techniques. This
process provides a means to sieve through process
risk, to identify high risk areas, and to deploy the
latest analytical techniques. By reducing uncertainty
in the assessment, investment in instrumented systems,
especially the safety instrumented systems (SIS),
for risk mitigation can be examined more realistically.
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SIS-TECH provides technical personnel, such as process and I&E engineers,
to facilitate your Process Hazards Analysis (PHA)
team.
Our personnel understand chemical engineering and control system design
practices. The PHA is conducted using any method acceptable to you,
such as brainstorming, what if/checklists, Hazard & Operability
(HAZOP) study, and layers of protection analysis (LOPA). If you do not
have established procedures, we can help you with that or we can use
our "proven-in-use" methods. SIS-TECH "proven-in-use" methods meet the
intent of government and industrial standards. Our LOPA method, in
particular, fulfills the intent of ANSI/ISA 84.00.01-2004 (IEC 61511
modified) and is consistent with the Center for Chemical Process Safety
concept book, Layer of Protection Analysis: Simplified Process Risk Assessment. When a SIS-TECH method is used,
the procedure is reviewed with a representative of
your company to ensure that the procedure adequately
represents your risk management philosophy.
No matter what PHA method is chosen,
the work process that we follow is similar:
- Process deviations from normal
operation are discussed,
- Initiating causes of process
deviations are identified,
- Initiating cause frequency
is determined,
- Likely consequence of each
initiating cause is evaluated and categorized by
severity.
- Various types of impact are
examined, such as personnel and community safety,
environmental damage, asset protection or business
interruption.
- Once the initiating cause
frequency and consequence severity are known, the
risk can be compared to the risk criteria to determine
whether safeguards are needed to mitigate the process
risk.
- If available safeguards are
insufficient to mitigate the risk, the team makes
recommendations for improvements.
- These recommendations are
prioritized based on the level of risk remaining
after applying existing safeguards.
The activity of PHA Facilitation includes advance
preparation of documentation to optimize the efficiency
of the study. The process unit is divided into appropriate
study nodes with notation of the design intent for
each study node. A tentative list of pertinent deviations
or question is also developed based on chosen methodology
to most effectively use your personnel's time. Our
goal is to minimize the amount of time your personnel
are involved as a team while adequately assessing
the mitigation of the potential process risk.
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At the conclusion of the PHA
(or H&RA),
a risk mitigation strategy must be defined to address risk identified
in the PHA and other analysis. The PHA often generates many
recommendations that must be reviewed to determine whether the
recommendation provides the most cost effective and reliable way to
mitigate the risk. Further, the PHA focused on mitigating individual
risk, which can lead to excessive safety instrumented system (SIS)
requirements. Risk should be mitigated with an overall risk mitigation
strategy that takes into account your reliability, operability and
maintainability needs. Our approach is to achieve the lowest cost of
safe automation by providing you with a mitigation strategy to minimize
your risk but maximize your production.
SIS-TECH provides technical personnel, such as process and I&E engineers with extensive end-user
experience. We like to think that "we've been
there and done that," due to our large customer
base and our personnel's previous work history. If
you have a problem that needs to be solved, we probably
have seen and implemented multiple approaches. Our
consultants can help you choose a solution that meets
your facility's needs.
The first step of the Independent Protection
Layer (IPL) reconciliation phase involves a review
of the PHA (or H&RA) results with your personnel
to ensure that we understand the needs of your production
process. Our senior consultant then works with your
personnel to develop a solid risk mitigation strategy
that builds upon the PHA team results, but considers
the following:
- Minimizing changes to the
existing SIS,
- Reducing capital cost associated
with new protection layers,
- Reducing required testing
interval, and
- Optimizing process reliability.
The senior consultant generates a report providing
the PHA reference number and the specific response
to each recommendation. This provides the necessary
management of change documentation.
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 The
safety integrity level (SIL) or the average
probability to fail on demand (PFDavg) of each safety
instrumented function is determined to ensure that
each safety instrumented function (SIF) achieves the
risk reduction allocated during the process hazards
analysis. Since the spurious trip potential can have
a significant effect on the lifecycle cost of the
SIF (SIF), we also determine the spurious trip rate.
Methodology: The verification is performed
by modeling each SIF using fault tree analysis, which
is a highly adaptable logic diagram based technique.
Software: Fault tree analysis is
used to calculate the PFDavg and the spurious trip
rate of each safety function. Tthe
calculation is performed using a SIS-TECH proprietary
software tool, SIL Solver™, or Isograph FaultTree+,
depending on the complexity of the safety function.
Databases: Any failure rate data will
be obtained from the SIS-TECH proprietary database.
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Auditing is simply an
activity to determine 1) whether you are doing what you need to do and
2) what you said you were going to do. Auditing requires an independent
person from the process unit management, having experience and
knowledge related to your process risk, safety instrumented system
(SIS) design, and operation and maintenance practices. The audit should
establish a path forward for addressing deficiencies and improving
reliability. SIS-TECH provides personnel who have field experience in
the operation, maintenance, and testing of SIS. These personnel
understand the intent of ANSI/ISA 84.00.01-2004 (IEC 61511 mod), as
well API, NFPA, and ASME standards, and have extensive experience in
applying these standards at chemical, petrochemical, and refining
companies.
Auditing provides a level of assurance
that the SIS is designed, installed, maintained and
tested to yield the target safe and reliable performance
over the SIS lifetime. The audit program is custom
tailored to your needs, reviewing SIS design basis
documents, function test plans and results, and management
of change controls. The audit may be a simple review
of detail design project documentation to verify that
the design is meeting the intent of the Hazard and
Risk Analysis (H&RA) and the design basis, or
it may be a multi-layered audit of the existing SISs.
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