Decision-making in the mining industry: An examination of risk-related judgements and decisions in the area of ground control, and the implications for training mining engineers

Abstract

Underlying most accidents in high-risk systems are latent conditions such as design and maintenance errors, arising predominantly from flawed high-level decisions. The mining industry is one such system, with accident investigations finding that mine planning and design decisions, often made by mining engineers, are one of the most common sources of latent conditions in this industry. Given this background, training aimed at improving mining engineers' decisions may help to prevent systemic design errors that lead to mine accidents.This thesis investigates ground control (i.e., rockfall prevention) decisions made by mining engineers in underground mines in order to arrive at recommendations for the optimal design of ground control education and training for mining engineers. A series of studies is described that investigate ground control decision-making (i.e., the decision process, strategy use, and information use); expertise-related changes in ground control decision-making; the influence of individual attributes (e.g., risk propensity, motivations, expectations, and risk perceptions) on risk decisions; and the effectiveness and relevance of current undergraduate ground control education. These topics are investigated using interview, questionnaire and judgment analysis methodologies, combining both process and structural approaches to provide complementary quantitative and qualitative data. The research draws on literature in the areas of risk decision-making, expertise, social judgment theory, signal detection theory, and naturalistic decision-making.Following an initial exploratory study to determine the specific decision area within the mining domain upon which to focus, three studies examine mining engineers' ground control decisions. The first study explored the mining domain by interviewing engineers, with subsequent questionnaire results indicating that ground control decisions are made frequently and have important safety-related consequences. Study 2 utilised the method of cognitive task analysis to obtain detailed information about ground control decision-making from experienced mining engineers. Study 3 investigated expert-novice differences in this area using judgment analysis and signal detection methods in a cross-sectional design. This study also explored the influence of a variety of individual and organisational attributes on risk decisions. The final study expanded on the findings of Study 3 by using a retrospective questionnaire design to assess the changes that occur in decision-making and in these individual attributes as recent mining engineering graduates become experienced engineers. This study also assessed the effectiveness and relevance of current undergraduate ground control education.Outcomes of the research include a list of critical cues and information sources used in ground control decision-making, and a preliminary model of the decision process. Findings suggest that the decision process can be divided into two main stages, consisting of the situation assessment (comprised of the risk assessment and the, failure diagnosis) and the support decision. The support decision also had two components, corresponding to the need for extra support (based on the risk assessment) and the type of support required (based on the failure diagnosis). These stages were differentiated in terms of cognitive processes and information use, with engineers appearing to use intuitive, recognitional matching strategies when assessing situations, and analytic strategies when making support decisions.Key findings of the studies point, firstly, to the importance of situation assessment, or the ability of mining engineers to read the ground. The results also suggest that a number of characteristics of decision-making change with experience, for example situation assessment abilities, and the ability to know which information is relevant. Finally, the studies identify a number of individual attributes (i.e., motivations, expectations, perceived control, hazard involvement and hazard knowledge) that may influence engineers' ground control risk decisions.Based on these findings, and a review of the training design literature, a number of recommendations for the design of effective and relevant ground control education and training are discussed. These recommendations concern the ability to assess risk, diagnose failure type, and make support decisions; and also address the need for engineers to be aware of how their values, expectations and risk perceptions may affect their ground control decisions. Limitations of the studies' methodologies and avenues for further research are also considered.