(110a) Methodology for Evaluation of Management of Safety Barries for Major Hazard Accidents

Evaluation of Management of Safety
Barries for Major Hazard Accidents

The last accidents in the process industries have
demonstrated and intensified the importance of the safety barriers to prevent
the occurrence of accidents.

The safety barriers, that are called preventive, if the
barrier could avoid the occurrence of accidents, or mitigating, if that
minimizes the consequences, can be identified by Preliminary Hazard Analysis, HAZOP
or LOPA studies, but no formal methodology is well established to evaluate the
integrity of this barriers. Normally, they are taken for granted and considered
to be operating well, based on information from

The purpose of this methodology is to evaluate the safety
barriers management, with focus on major accidents, in other to monitor the
barriers integrity. In order to evaluate this, an audit methodology has been
developed to identify possible gaps on the management of the safety barriers.
This process analyses the main barriers and safeguards used in the process
industries risk analysis and it is usually conducted by the plant safety
process team with the support of the other areas: inspection, maintenance,
instrumentation, engineering, safety and environment.

Best engineering and process safety management best practices
have been used to define the requirements that a barrier should follow to
guarantee its well established management. For each type of barriers there are questions
related of the barriers management.

A protocol, specific for each scenario identified on the risk
assessment studies, is used, as illustrated in Figure 1.

Figure 1 ? Example of Protocol with Identification of
Barriers

For Inspection and Maintenance Program, as an example of
preventive barriers, some questions are key for the
management of this: existence of inspection plan; documentation of the plan; inspections
performed according; and management of recommendations from inspections; revision
and update of the plan. All these question shall be
answered considering the specific conditions of the system, equipement or
instruments involved on the scenario.An example is indicated in Figure 2
bellow.

Figure 2 ? Example of Protocol for evaluation of Inspection
Program

These questions must be answered with YES or NO and at least
one NO answer is indicates that the barrier is potentially compromised. In
other words, if one step of the management cycle is not being performed, this
can lead to a potentially comprimised barrier that can lead to an accident, considering
the Swiss Cheese Accident Model from
James Reason.

The
results of the barriers audit indicates that the potentially compromised
barriers what will generate an action plan for barriers integrity management. Both
specific and systemic actions are identified and shall be implemented in order
to guarantee the better management of the safety barriers.

Main differentiator of this
methodology and sistemic approachs for Process Safety Management System
evalution is the focus on the barriers and requirements for its management.

Additionally several
indicators and statistics can be generated over the process of auditing, evaluating
areas that requires greater investiments (as safety, maintenance, inspection,
instrumentation), best practices can be shared among different sites of same
company and an overview for communication with leadership can be developed,
bringing a new view of the process safety management system.