Control of Accidents

To control the accidents the following two theories are applied in general.

"Seven Avenues" Theory

After discussing all models it can be concluded that there are following seven avenues to initiate the countermeasures:

  1. Safety management error
  2. Safety program defect
  3. Management / Command error
  4. System defect
  5. Operating error
  6. Mishap
  7. Consequence

Safety management error: For this avenue the attention should be on

  • Training
  • Education
  • Motivation
  • Task design

Safety program defect: This avenue addresses about proper data collection and analysis before data are applied for removing the defects and hence the following should be the key issues:

  • Information revision
  • Data collection
  • Data analysis and application in implementation

Management / Command error: For the management and control of any possible error or incidents the importance of training cannot be ignored. Training may not have desired impacts in error control mechanism if minimum basic education is missing. A various serious task of task design is needed with proper motivation. In brief the effective management of error will have following:

  • Training
  • Education
  • Motivation
  • Task design

System defect: To overcome the system defects either engineering modification is required at the early with revised and effective standard operating procedures (SOPs), proper enforcement of national regulations and company policy/statements by circulars

  • Design revision
  • SOP
  • Enforcement and monitoring of Regulation and company policy

Operating error: It has been observed that operating errors leads to small accidents and if these small accidents have not been proper addressed then any one of the small accident may become the major accident. The operating error can be controlled effectively by:

  • Engineering control
  • Training and awareness
  • Motivation

Mishap: After having all avenues at their appropriate places when the accident occurs the only the following ways helps in reducing the damages of the accidents:

  • Protective equipments
  • Barriers
  • Separations

Consequence: Any accident has certain short term and a few long term impacts on human lives, environment, property hence to reduce the effect of consequences the following issues should be reviewed rigorously by all stakeholders:

  • Containment
  • Firefighting
  • Rescue and rehabilitation
  • Evacuation
  • First aid

Barriers theory

A key stage in any accident model is establishing the barriers that failed as well as those that worked. Barriers can take a number of different forms; normally technical (physical), administrative (procedures), or people-based, (training, competence, etc). There are also 'fortunate mitigating circumstances'. Time of day or night and weather (including wind direction) have played a part in reducing the effects of some major incidents but they should never be relied upon as a normal barrier as they cannot be controlled.

Once securing evidence, data collection, and interviews are completed, creating a time-line is normally the next stage in any Process Safety Incident Investigative Technique. From the time-line a probable sequence of events can be established and discrepancies, omissions and areas to explore further can be identified. Whilst this process does not identify the root cause of an incident directly, it tracks the sequence of events and barriers present and therefore allows all the relevant barriers to be identified. It then identifies which barriers worked effectively, which worked partially, but for which we have reduced confidence in their integrity, and which failed completely. In a typical process safety incident there will be barriers in all these categories. Further techniques can then be used to identify root causes for barrier failures and hence management system failures. Barrier identification also has additional benefits; it enables consideration to be given to barriers that could / should have been present, it enables the effectiveness of barriers to be assessed, it can aid with a Layer of Protection Analysis (LOPA), and finally, results can also be used to update predictive methods such as Hazard Identification (HAZID) and Hazard & Operability (HAZOP) Studies.

For process safety there are multiple barriers of disparate types and therefore a more sequential approach is needed. The most powerful approach has been to apply a formal root cause technique to each failed barrier in turn. This may seem time-consuming, but experience has shown that each barrier failure is typically due to a small sub-set of management system failures. Therefore it is relatively quick to analyse each barrier with the benefit of more rigorous analysis.

Once all the individual barrier root causes have been determined, the results can be collated to provide the overall assessment. At this point an approach with a pre-worked checklist of specific, defined, root causes ideally linked to management system elements becomes a powerful tool, since common root causes (those which under-pinned several barrier failures) become immediately apparent. This is an important management insight because it highlights those areas which should be addressed to strengthen the management system. If this process is repeated over time for each incident that occurs, a repeating picture of the common management system failings can be identified. With sufficient data this can be applied retrospectively. The figure above shows a barrier pattern for all three types to control any accident.

Deming Model

" The Safety Management System should set out the safety objective....the system by which these objectives are to be achieved, and the performance standards which are to be met and the means by which adherence to the standard is to be monitored."

The approach of Quality Management Model sometimes called "Deming Model" or "PDCA" is a complete loop system. This will ensure that the standard or quality will be achieved and the effectiveness of the management system is well monitored and improved continuously within the system.



The following checklist will help in PDCA:

Organizational issues:

  • time pressures to sustain on-time operations to achieve goals;
  • aging equipments requires intensive inspections for fatigue, corrosion, overall condition, etc.;
  • new technologies requiring new tools, new work procedures, costly retraining, etc.;
  • "fix-it" focus to stay on schedule (e.g. replacing broken parts without determination as to why)
  • outsourcing of services to subcontractors;
  • unwitting introduction of (lower cost, substandard) bogus parts, etc.; and
  • licensing and regulatory clearances;

Work site conditions:

  • plant designs that are not user-friendly from a maintenance perspective
  • control equipments and calibration (which are continually subject to modifications) versus standardization of maintenance tasks and procedures;
  • availability (and accessibility) of spares, tools, documentation, etc.;
  • requirements for having ready access to voluminous technical information, and the need for maintaining detailed work records;
  • variable environmental factors (for example, too hot or noise or less illumination, etc in the technical workshops and process areas);
  • unique operating conditions created by concurrent activities and inclement weather

Human Factors in maintenance:

  • organizational and working conditions (as described above);
  • environmental factors (e.g. temperature, lighting and noise);
  • individual factors (e.g. workload, physical demands and maintenance);
  • scheduling (e.g. shift work, night work and overtime) versus adequacy of rest periods;
  • appropriateness of SOPs (e.g. correctness, understandability and usability);
  • quality of supervision;
  • proper use of job cards, etc. (i.e. do actual floor practices comply with SOPs?); adequacy of formal training, on-the-job training (OJT), recurrent training and Human Factors training;
  • adequacy of hand overs at shift changes and record keeping;
  • boredom; and
  • cultural factors


Locations of visitors to this page