Using the MORT Approach
The Management Oversight and Risk Tree (MORT) approach delves into the relationship between the flow of energy or activity and the barriers. In line with this, the analysis starts by differentiating between the control and the safety barriers.
Control barriers are distinguished as those that are in place where energy used is part of the normal occurrence. Examples of control obstructions or preventive measures include:
- regulatory inspections for approved design and work methods
- regular internal checks and maintenance
- adequate job training of operators
- physical control and management of hazardous materials
- circuit breakers or automated disconnection switches
- pressure vessels or containers
Safety or Protective barriers, on the other hand, deal with energy that is not related to the workflow; hence it is unintended or unwanted. This includes:
- protective guard rails
- preventive equipment
- fire drills or other simulation exercises
- emergency contingency or mitigation plans.
However, these barriers will be further classified according to their purpose, whether they are for control or for preventive measures or for mitigating actions. This is being done in order to determine if each obstruction is independent of a task or if it is a part of the task. It can also be the plan in place as a means to curtail the effects of the incident in the event that all safety controls fail.
The Barrier Location – this is another important aspect of the MORT approach. The chart should indicate at what point the obstructions or preventions are located. This applies to accidents that are instigated by a physical activity, and the obstructions may be located at
:(1) the source of energy or activity,
(2) a time period or space before the preventive control is activated, and at
(3) the instance that the untoward incident or accident happens.
Other classifications to consider in applying the MORT approach are the nature or element of the barrier in place, whether the function is:
Physical, in the sense that it prevents the happening or the release of the energy that can cause a trigger factor to happen. The obstacles could be in the form of concrete or steel walls, fences, containers, valves, harnesses, sprinklers, filters, air bags, etc.
Functional, which applies to the prevention of movement like locks, passwords, action or numbered sequences, brakes, time-delays, interlocking devices, etc.
Symbolic, like flashing lights, labels, color transformation, alarms, approvals or clearance.
Non-physical, which pertains to monitoring and supervision and the implementation of laws, rules and regulations, or the observance of guidelines, ethics, and checklists or the adherence to restrictions and prohibitions.
However, these classifications are dependent on the activities or energy for which the controls have to be applied.