*Corresponding author. Email address: sa_oke@yahoo.com doi: 10.14456/kkuenj.2016.32 KKU ENGINEERING JOURNAL October – December 2016;43(4):166-171 Research Article KKU Engineering Journal https://www.tci-thaijo.org/index.php/easr/index Published by the Faculty of Engineering, Khon Kaen University, Thailand Applying the decision trial and evaluation laboratory method as a decision tool for an effective safety management system in aviation transport Ifeanyichukwu Ebubechukwu Onyegiri and Sunday Ayoola Oke* Department of Mechanical Engineering, Room 10 Mezzanine Complex, Faculty of Engineering, University of Lagos, Lagos, Nigeria Received December 2015 Accepted January 2016 Abstract In recent years, weak engineering controls and lapses in the aviation industry associated with safety management systems (SMSs) have been responsible for seemingly unprecedented disasters. A previous study confirmed the difficulties experienced by safety managers with SMSs and the need to direct research to this area of investigation for more insights and progress in the evaluation and maintenance of SMSs. The purpose of this work is to examine the application of the Decision Trial and Evaluation Laboratory (DEMATEL) method to the aviation industry in developing countries, illustrating the Nigerian aviation survey data for the validation of the method. The advantage of this procedure over other decision making methods is in its ability to apply feedback in decision making. It also affords us the opportunity of breaking down complex aviation SMS components and elements that are multi-variate in nature through analysis of their contributions from the perspective of cause and effects. This in turn yields easier and more effective aviation transportation accident pre-corrective actions. In this work, six revised components of an SMS were identified and DEMATEL was applied to obtain their direct and indirect impacts and influences on the overall SMS performance. Data collection was by a survey questionnaire, which served as the initial direct- relationship matrix, coded in Matlab software for establishing an impact relation map (IRM). The IRM was then plotted in an Excel spreadsheet. From our results, the safety structure and regulations had the highest positive impact on an SMS. The results agree with those of previous researchers who used grey relational analysis. Thus, DEMATEL serves as a valid tool and resource for safety managers. Keywords: DEMATEL, Safety manager, Relationship matrix, Safety management system 1. Introduction Globally and in recent years, the aviation industry in developing countries of the world more frequently experience accidents, which are disasters that account for financial and property wreckages and great loss of lives. The corresponding causes of these disasters are the weak engineering controls and lapses associated with safety management systems (SMSs) in the aviation industry [1]. The implication of these safety loopholes is that the frequent accident occurrences globally, high fatalities and injury rates linked to aviation transportation make this means of transportation very dangerous to both aviation service customers and the employees. This threat must stop. Urgent corrective actions must be implemented to stop this unwarranted situation. As a starting point in achieving the above stated pursuit, the complex safety management system (SMS) is analysed and made more attractive and useful in the safety managers decision making by the application of Decision Making Trail and Evaluation Laboratory (DEMATEL) [2-5]. The historical development of DEMATEL could be traced to the 1970s when the Science and Human Affairs (SHA) programme located in the Battle Memorial Institute (BMI), Geneva evolved this decision making tool that easily allows scientists to disintegrate the complex multi-variate set of components through systematic analysis that permits the diverse system criteria from the perspectives of their causes and effects. The result is that decision making is made easier and increasingly effective. An advantage of DEMATEL is that it helps in the clarification of the interrelationships among the complex factor of a system from the perspective of influences that each factor has on every other factor [6-7]. DEMATEL is one of the most promising research tools in decision sciences, which has garnered scholarly attention over the past several years. The use of DEMATEL has increased greatly from earlier years, with studies documenting theoretical and practical examinations of a wide array of systems, including cost of quality selection [8], human resources management [9], auto spare-parts industry [10], information technology [11-12], educational institutions [13], park and recreation activities [14] and EDA industry [15]. Prior studies have focused largely on integrating concepts with DEMATEL as a good and effective approach of deriving the most benefits of DEMATEL, bringing out novel concepts under different nomenclature.