A method,DEB analysis,for proactive risk analysis applied to air traffic control

Introduction: Complex production systems as, for instance, those used in health care, in off shore industry, in nuclear power industry or in aviation suffer now and then from severe system breakdowns. Lessons learnt from these often lead to changes in the “system”. A more rational approach would be to identify these “system weaknesses” before accidents happen.A new proactive method, DEB analysis, for identifying hazards in a complex system was applied to an air traffic control unit in Malmoe, Sweden. The system weaknesses (i.e. latent system failures and insufficient safety barriers), which could cause these hazards, were identified. The effectiveness of the method was assessed by comparing these “prospective” identified system weaknesses with “retrospective” identified system weaknesses in a consecutive series of loss of separation cases (n=15), investigated by the central aviation administration.Main findings: The system weaknesses in 14 out of the 15 cases were found with the proactive method. One sub-task was missed.Discussion: The method is an effective tool in disclosing system weaknesses that can give rise to hazards. The method should be modified with increased engagement of operators. It might be applied to other complex systems as well.