Coal Mining Safety Management Efficiency And Its Constraints

Safety management is an important way to ensure the safety condition of a coalmine besides safety techniques.However, the core of safety management is efficiency that obtaining the satisfactory safety effects uses the safety management resources as little as possible. This work is to improve the coal mining safety management efficiency(CMSME).The following steps is to investigate the CMSME. First, evaluating the safety management efficiency of a coalmine is to learn its level of CMSME based on the evaluation index system, as is carried out through comparing with other coalmines with different scales and geology conditions in China. And the the evaluation result may help the leaders make an effective decision. Then the excellent benchmark values for all indices as are the bases for further research will be determined by selecting the coalmines with excellent CMSME. Second, identifying the constraints of the coalmine and breaking through them on some time are to improve its safety management efficiency by the proposed constraint factor identification model. Finally, controlling the safety management effects and safety management resources of it on special time during the production by earned value method is to fulfil the schedule of safety management effects with safety management resources the less the better.The definition of CMSME was given: safety effects were acquired based on safety bases with safety management resources input under some period. Based on the definition, an index system was built for evaluating CMSME including 25 indices classified into safety effects, safety bases and safety management.Evaluating the relative CMSME of a coalmine is to compare its every index value with that of other coalmines comprehensively. A target center is necessary in the grey target decisiom method, which is composed of the best values of every index by comparing with indices of all alternatives. Then, all alternatives are ranked by their target center distances with the smaller the better. However, the generalized grey target decision method proposed in this dissertation considering the target center based on the decision maker’s preferences could handle mixed attributes including real and fuzzy numbers in a united method. Fowllowing this, the group experts’ order preferences relation method for solving the weights of all indices improved by the author could deal with the experts of even number as well as the improved method for assigning weights to the experts objectively. Furthermore the projection pursuit model was introduced to aid the decisiom making, which is able to classify some alternatives well even for high-dimensional and non-normal distribution samples. Case study showed that: ten coalmines were classified into three classes about their CMSME by the projection pursuit model. However, weather considering the decision maker’s preferences or not the ranking of excellent CMSME remained the same. Based on the results, some coalmines with excellent CMSME were selected to determine the excellent benchmark values for all indices. Finally, the classification of CMSME was given by the integrated target center distances.A mathematical model identifying the constraints judged by contribute degrees and excellent benchmark values of all factors was constructed with the principle of comparision with changes of the ratio of integrated CMSME and the ratio of each impact factor. The case study of Quandian coalmine showed: the bottleneck constraint factors in July were morality per million tons, rate of eliminating latent dangers, timeliness of latent dangers correction. Then the integrated CMSME had been obviously improved from 0.4206 in July to 0.7271 in December through removing the bottleneck constraint factors.Finally, an earned value method for CMSME was built to control the safety effects and the safety management resources during the production based on the schedule of CMSME. It fulfils its task depending on 4 evaluation indices including resource variance, effect variance, and resource performed index and effect performed index which are from regularly comparing the intermediate variable earned value for safety management efficiency with the variables budget value for safety management efficiency and actual value for safety management efficiency. The case study of Quandian coalmine showed the model was useful to control the safety management effects and safety management resources during the production, and problems might be found and solved timely.The general conclusions are as follows.(1) It is helpful to improve the CMSME by identifing the constraints and breaking through them timely during the production.(2) It may have one or more constraints even the coalmine’s CMSME is high on some time.(3) It is compulsory to control the CMSME during the production, and problems in management can be found and solved timely.(4) The CMSME is dynamic, which may be kept in a relative steady state and high level through managing and controlling it.(5) The qualitative indices of CMSME are easier to control than that of quantitative indices.