Document Type

Conference Paper

Publication Date


Publication Details

This conference paper was originally published as Sinha, SK, Risk Management in Mines - The Six Sigma Way in Aziz, N (ed), Coal 2008: Coal Operators' Conference, University of Wollongong & the Australasian Institute of Mining and Metallurgy, 2008, 231-244.


As the mining industry strives to become a zero defect/harm sector, the concept of risk management using Six Sigma quality management principles for consistency and standardisation of processes/actions and the effect thereof is currently been practiced in Indian coal mines. For monitoring of the effectiveness of actions as recommended under a risk management exercise, the process and corresponding defect are predefined in a statistical manner. A series of frequency distribution patterns and defects in statistical count are generated. The defects measured per million opportunities against each activity/process and thus the corresponding sigma level of process performance is applied. In order to build up system capabilities and graduate towards higher sigma levels of operation, the backbone exercise of Six Sigma management system is reached by carrying out the failure mode effect analysis (FMEA). Each potential failure mode component is assessed for its severity (S), occurrence (O) and detection (D). Detection is measured on an inverse scale of (1-10). To build up system capabilities in risk management, the recommendations of FMEA are implemented. Subsequently the potential failure mode component(s) are reassessed for their S, O and D. With every evolution in the system, as it slowly graduates towards becoming a Six Sigma risk management system, the risk priority number (RPN) should go on decreasing. A case study of a roof bolting exercise is presented as an example.