38
Sensemaking in Safety Critical and Complex Situations
Step 4. Evaluation. The fourth step is to evaluate task characteristics ( complexity,
time available, communication, etc.) and failures to optimize human performance
( reliability) through improvement in design features ( e.g. HMI and alarm systems)
as well as to generate requirements for how the operational barrier element shall be
executed, when and by who.
Step 5. Implementation. The fifth and final step consists of implementing the
findings from the evaluation ( Step 4) into relevant design specifications, operational
and emergency procedures, other governing documents, and training or competence
programs. An important part of documenting the operational barrier elements and
associated performance requirements was to include them as part of the installations
safety ( barrier) strategy.
A more detailed description of an operational barrier element mapping and assessment case study can be read in a chapter written by Ludvigsen et al. ( 2018).
GUIDANCE ( MISSING) ON HOW TO IDENTIFY
OPERATIONAL BARRIER ELEMENTS
Developing the process for mapping and assessing operational barrier elements
started with reviewing available methodologies for Step 1: Identification. The guidance for safety critical task analysis issued by Health and Safety Executive UK and
EI both contain tools and examples for how to identify safety critical tasks and rank
their criticality. These were therefore reviewed as a starting point towards establishing a suitable approach.
Health and Safety Executive UK’s guidance recommendation for identification
of safety critical tasks is to have people “ brainstorm” around certain topics such as
equipment, phases of operation, task types and job descriptions. However, no specific
methodological approach is described. Instead, a set of “ generic critical task inventories” are provided to use as a starting point. As it turned out, the listed tasks mainly
reflect high-level operational activities, such as those related to separation, oil export,
gas dehydration and gas compression for production facilities, and drilling, pumping,
reeling and hoisting for rig operations. Due to being described at a relatively high
level of detail, checks revealed that subsequent determination of task criticality levels
proved difficult without closer examination, which in turn would defeat the purpose
of safety critical task identification and screening. Subsets of operations required
for handling abnormalities and emergencies, which are closer to the definition of
operational barrier elements, were covered to a less extent. As such, neither the task
inventory nor the safety critical task identification approach suggested by Health and
Safety Executive UK could be applied directly for the purpose of identifying operational barrier elements.
To further understand the specific needs behind how to identify operational barrier elements, it can be useful to put the definition into a broader context. The PSA
distinguishes between risk reduction through use of safe and robust solutions, and
risk reduction by implementation of barriers ( PSA, 2017, see Figure 3.2).
“ Robust solutions” refer to those which prevent the likelihood of hazardous events
being initiated in the first place, such as use of inherent safe design principles by
removing hazards instead of controlling them. It may however also refer to operations
Sensemaking in Safety Critical and Complex Situations
Step 4. Evaluation. The fourth step is to evaluate task characteristics ( complexity,
time available, communication, etc.) and failures to optimize human performance
( reliability) through improvement in design features ( e.g. HMI and alarm systems)
as well as to generate requirements for how the operational barrier element shall be
executed, when and by who.
Step 5. Implementation. The fifth and final step consists of implementing the
findings from the evaluation ( Step 4) into relevant design specifications, operational
and emergency procedures, other governing documents, and training or competence
programs. An important part of documenting the operational barrier elements and
associated performance requirements was to include them as part of the installations
safety ( barrier) strategy.
A more detailed description of an operational barrier element mapping and assessment case study can be read in a chapter written by Ludvigsen et al. ( 2018).
GUIDANCE ( MISSING) ON HOW TO IDENTIFY
OPERATIONAL BARRIER ELEMENTS
Developing the process for mapping and assessing operational barrier elements
started with reviewing available methodologies for Step 1: Identification. The guidance for safety critical task analysis issued by Health and Safety Executive UK and
EI both contain tools and examples for how to identify safety critical tasks and rank
their criticality. These were therefore reviewed as a starting point towards establishing a suitable approach.
Health and Safety Executive UK’s guidance recommendation for identification
of safety critical tasks is to have people “ brainstorm” around certain topics such as
equipment, phases of operation, task types and job descriptions. However, no specific
methodological approach is described. Instead, a set of “ generic critical task inventories” are provided to use as a starting point. As it turned out, the listed tasks mainly
reflect high-level operational activities, such as those related to separation, oil export,
gas dehydration and gas compression for production facilities, and drilling, pumping,
reeling and hoisting for rig operations. Due to being described at a relatively high
level of detail, checks revealed that subsequent determination of task criticality levels
proved difficult without closer examination, which in turn would defeat the purpose
of safety critical task identification and screening. Subsets of operations required
for handling abnormalities and emergencies, which are closer to the definition of
operational barrier elements, were covered to a less extent. As such, neither the task
inventory nor the safety critical task identification approach suggested by Health and
Safety Executive UK could be applied directly for the purpose of identifying operational barrier elements.
To further understand the specific needs behind how to identify operational barrier elements, it can be useful to put the definition into a broader context. The PSA
distinguishes between risk reduction through use of safe and robust solutions, and
risk reduction by implementation of barriers ( PSA, 2017, see Figure 3.2).
“ Robust solutions” refer to those which prevent the likelihood of hazardous events
being initiated in the first place, such as use of inherent safe design principles by
removing hazards instead of controlling them. It may however also refer to operations