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Analysis of unsafe situations in industrial processes based on system dynamics and organizational theory

Boukas Dimitrios

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Year 2018
Type of Item Doctoral Dissertation
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The purpose of the current Ph.D. thesis is the use of System Dynamics method in proposing a Risk Assessment Model that analyzes the work system and industrial processes of a typical mine in order to consider many unsafe scenarios and incidents. The mining industry is still ranked highly among the economic sectors with the highest fatality rates. Earlier safety failures have been attributed to the lack of a comprehensive Safety Management System that employs effective barriers. The Safety Management System is influenced by the safety perspective adopted by the firm. The thesis has used two prominent safety perspectives to develop a Synthetic Model of safety, that is: the Systemic Approach of Safety and the Systemic Control and Cybernetics Theory. In particular, risk is represented as a dynamic variable that emerges through safety interactions between technical, workplace and organizational factors. The proposed model views safety within the overall framework of organizational performance in managing a variety of subsystems, each with their own demands and constraints. This is in contrast to more traditional approaches where incidents have been seen as the result of failures of individual elements such as workers, supervisors, procedures or equipment.The thesis contributes to the development of original scientific knowledge where the possibility of an incident occurring depends both on the willingness of employees and managers to make more effort, as well as on the employees' mental capabilities. Specifically, the new model incorporates the organizational culture of management and employees as well as the effect of human reliability in an effort to examine how risk evolves over time. The latter is influenced by many factors such as, employee strategies and practices, the way in which work is organized and the wider work system.The Synthetic Model consists of four work subsystems: the Safety Subsystem, the Production, the Human Resources and the Task Backlog & Errors Subsystem. The simulation model has tested a number of scenarios in a sensitivity analysis with the Vensim software and several conclusions were reached. For example, human reliability is very important for the safety of production facilities. However, the systematic study of human error has been neglected in industrial facilities for various reasons as shown in this thesis. In general, it has been shown that human errors are fatal when workers find themselves in situations that increase the workload, make communication difficult and make it difficult to repair unsuccessful attempts. Accidents occur when operator mistakes combine with a series of unsafe working conditions, the control of which is effectively exercised by the company's management.The modelling of the typical mine sought to explore the feasibility of the proposed method rather than perform a realistic numerical estimation of all risks involved in mining operations. Several organizational processes have already been explored by previous studies and hence, they were not further discussed in the present thesis. This allowed more space to focus on organizational processes that have not received much attention in the literature. System dynamics is a promising approach that invites further studies to examine other types of system exploration such as, ability of organizations to learn from incidents, new safety management systems, relationships between different stakeholders (e.g., owners, contractors, supervisors), new systems of risk communication and so on. Thus, organizations can build their own models of safety management and use them as tools for further improvement.

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