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  • 401.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    TPM framework for underground mobile mining equipment: a case study2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    In underground mines, mobile mining equipment is critical to the production system. Drill rigs for development and production, vehicles for charging holes, LHDs for loading and transportation, scaling rigs and rigs for reinforcement and cable bolting are all important units in the process to generate a continuous ore flow. For today’s mining companies, high equipment availability is essential to reduce operational and capital costs and to maintain high production. High and controllable reliability is also important especially in attempts to automate the production equipment. This paper compares existing maintenance work in a Swedish and a Tanzanian mine. The various maintenance procedures are identified and evaluated based on a TPM framework.

  • 402.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Production and maintenance performance analysis: manual versus semi-automatic LHDs2013Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 19, nr 1, s. 74-88Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose – The purpose of this paper is to evaluate and analyse the production and maintenance performance of a manual and a semi-automatic Load Haul Dump (LHD machine to find similarities and differences.Design/methodology/approach – Real time process-, operational- and maintenance data, from an underground mine in Sweden, have been refined and aggregated into KPIs in order to make the comparison between the LHDs.Findings – The main finding is the demonstration of how production and maintenance data can be improved through information fusion, showing some unexpected result for maintenance of automatic and semi-automatic LHDs in the mining industry. It was found that up to one third of the manually entered workshop data are not consistent with the automatically recorded production times. It is found that there are similarities in utilization and filling rate but differences in produced tonnes/machine hour between the two machines.Originality/value – The originality in this paper is the information fusion between automatically produced production data and maintenance data which increases the accuracy of reliability analysis data. Combining the production indicator and the maintenance indicator gives a common tool to the production and maintenance departments. This paper shows the difference in both maintenance and production performance between a manual and semi-automatic LHD.

  • 403.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    The influence of the operating environment on manual and automated load-haul-dump machines: a fault tree analysis2013Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 27, nr 2, s. 75-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The automated load-haul-dump (LHD) machines have the potential to increaseproductivity and improve safety, but there are many issues to be considered when optimising the operation of LHDs. Today’s focus on improved equipment reliability is part of the problem, and another difficult issue is the special conditions and constraints of the operating environment. For automated LHDs, the latter issue is even more important, as humans have been removed from the production area and are not close by to solve the problems. The purpose of this paper is to find the causes of LHD idle time and to study their impact on the operation of LHDs. In this study, real-time process data and maintenance data from an underground mine in Sweden have been refined and integrated. The study takes into account the complexity of the mine environment, discusses the factors to be considered when optimising and automating the operation and uses fault tree analysis (FTA) to analyse the idle time.

  • 404.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ghosh, Rajib
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Bolting Procedures in Outokumpu’s Kemi Mine2014Ingår i: Mine Planning and Equipment Selection: Proceedings of the 22nd MPES Conference, Dresden, Germany, 14th – 19th October 2013 / [ed] Raj Singhal ; Carsten Drebenstedt, Encyclopedia of Global Archaeology/Springer Verlag, 2014, Vol. 3, s. 411-420Konferensbidrag (Refereegranskat)
    Abstract [en]

    The working environment for ground support installation in mines has improved a lot during the last 20-30 years, with more and more mechanized installations of the different ground support elements such as bolts, cable bolts and screen. However ground support installation productivity has not followed the same development curve. In fact, its productivity has more or less remained constant and in some cases has even fallen if, as an example, comparisons are made between the manual and mechanized installations of bolts. One reason for this is that modern mechanised bolt rigs are very complex, capable to perform many tasks. To be able to fully utilize this equipment’s capability a different level of maintenance and product support is required. This paper describes the bolting process in Outokumpu’s Kemi mine that has a very interesting procedure for bolt installation and has also paid an unsurpassed attention to the maintenance procedures to improve productivity.

  • 405.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability analysis and comparison between automatic and manual load haul dump machines2015Ingår i: Quality and Reliability Engineering International, ISSN 0748-8017, E-ISSN 1099-1638, Vol. 31, nr 3, s. 523-531Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Today's trend of replacing manually operated vehicles with automated ones will have an impact not only on machine design, working environment and procedures but also on machine breakdown and maintenance procedures. In the harsh environment of underground mines, the transition from manual to automatic operation is believed to fundamentally change the basis for break downs, maintenance and machine design. In this paper, differences and similarities between manual and automatic underground loading equipment is analysed from a reliability point of view. The analysis is based on a case study performed at a Swedish underground mine. In the contrary of common thoughts, this paper proves that there is a difference between the manual and semi-automatic machines and in particular for the transmission, in favour of the manual one. This paper also shows a path for detailed reliability analysis, and the results may be used for improving maintenance programmes for other types of mobile equipment

  • 406.
    Göhler, Martin
    et al.
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Noise radiation from a diesel engine: noise control investigations on the timing cover1991Rapport (Övrigt vetenskapligt)
  • 407.
    Haarakoski, Milla
    et al.
    University of Lapland, Rovaniemi.
    Johansson, Maria
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    A guide to methods for small and medium sized enterprises (SMEs) designing for new markets, based on cultural research experiences2006Ingår i: Wonderground: Design Research Society International Conference 2006, Proceeding book / [ed] Ken Friedman; Terence Love; Eduardo Côrte-Real; Chris Rust, Lisbon: CEIADE – Centro Editorial do IADE , 2006Konferensbidrag (Refereegranskat)
  • 408.
    Haidong, Shao
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China. College of Mechanical and Vehicle Engineering, Hunan University, Changsha, China.
    Junsheng, Cheng
    State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China. College of Mechanical and Vehicle Engineering, Hunan University, Changsha, China.
    Hongkai, Jiang
    School of Aeronautics, Northwestern Polytechnical University, Xi’an, China.
    Yu, Yang
    State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China. College of Mechanical and Vehicle Engineering, Hunan University, Changsha, China.
    Zhantao, Wu
    State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China. College of Mechanical and Vehicle Engineering, Hunan University, Changsha, China.
    Enhanced deep gated recurrent unit and complex wavelet packet energy moment entropy for early fault prognosis of bearing2019Ingår i: Knowledge-Based Systems, ISSN 0950-7051, E-ISSN 1872-7409Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Early fault prognosis of bearing is a very meaningful yet challenging task to improve the security of rotating machinery. For this purpose, a novel method based on enhanced deep gated recurrent unit and complex wavelet packet energy moment entropy is proposed in this paper. First, complex wavelet packet energy moment entropy is defined as a new monitoring index to characterize bearing performance degradation. Second, deep gated recurrent unit network is constructed to capture the nonlinear mapping relationship hidden in the defined monitoring index. Finally, a modified training algorithm based on learning rate decay strategy is developed to enhance the prognosis capability of the constructed deep model. The proposed method is applied to analyze the simulated and experimental signals of bearing. The results demonstrate that the proposed method is more superior in sensibility and accuracy to the existing methods.

  • 409.
    Hammar, Carsten
    et al.
    Skogshälsan, Boden.
    Eriksson, Ingvar
    Skogshälsan, Boden.
    Sundbäck, Ulrik
    Luleå tekniska universitet.
    Tingvall, Bror
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Helkroppsvibrationer i skogsmaskiner: skördare1980Rapport (Övrigt vetenskapligt)
  • 410.
    Hamodi, Hussan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability and Life Cycle Cost Modelling of Mining Drilling Rigs2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In the context of mining, drilling is the process of making holes in the face and walls of underground mine rooms, to prepare those rooms for the subsequent operation, which is the charging process. Due to the nature of the task, drilling incurs a high number of drilling rig failures. Through a combination of a harsh environment (characterised by dust, high humidity, etc.), the operating context, and reliability and maintainability issues, drilling rigs are identified as a major contributor to unplanned downtime.The purpose of the research performed for this thesis has been to develop methods that can be used to identify the problems affecting drilling rig downtime and to identify the economic lifetime of drilling rigs. New models have been developed for calculating the optimum replacement time of drilling rigs. These models can also be used for other machines which have repairable or replaceable components. Based on an analysis performed in a case study, a life cycle cost (LCC) optimization model has been developed, taking the most important factors affecting the economic replacement time of drilling rigs into consideration. To this end, research literature studies, case studies, and simulation studies have been performed, interviews have been held, observations have been made and data have been collected. For the data analysis, theories and methodologies within reliability, maintainability, ergonomics and optimization have been combined with the best practices from the related industries.Firstly, this thesis analyses the downtime of the studied drilling rigs, with the precision and uncertainty of the estimation at a given confidence level, along with the factors influencing the failures. Secondly, the thesis identifies components that significantly contribute to the downtime and the reason for that downtime (maintainability and/or reliability problems). Based on the failure analysis, some minor suggestions have been made as to how to improve the critical components of the drilling rig. Thirdly, a new method is proposed that can help decision makers to identify the replacement time of reparable equipment from an economic point of view. Finally, the thesis proposes a method using the artificial neural network (ANN) for predicting the economic lifetime of drilling rigs through a series of basic weights and response functions. This ANN-based method can be made available to engineers without the use of complicated software.Most of the results are related to specific industrial and scientific challenges, such as planning for cost-effectiveness. The results of the case study are promising for the possibility of making a significant reduction in the LCC by optimizing the lifetime. The results have been verified through interaction with experienced practitioners from both the manufacturer and the mining company using the drilling rig in question.

  • 411.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahmadzadeh, Farzaneh
    Division of Product Realization, Mälardalen University, Eskilstuna.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Economic lifetime prediction of a mining drilling machine using an artificial neural network2014Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 28, nr 5, s. 311-322Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study develops models for predicting the economic lifetime of drilling machines used in mining. It uses three cases, each represented by a MATLAB code, to develop an optimisation model. The resulting ORT is fed as input to an artificial neural network (ANN) and the results translated into a relatively simple equation. The study finds that increasing the purchase price and decreasing the operating and maintenance costs will increase a machine's ORT linearly. Decreased maintenance cost has the largest impact on ORT, followed by increased purchase price and decreased operating cost. The ANN method gives a series of basic weight and response functions which can be made available to any engineer without the use of complicated software. It also helps decision-makers determine the best time economically to replace an old machine with a new one; thus, it can be extended to more general applications in the mining industry

  • 412.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Aljumaili, Mustafa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Data Quality of Maintenance Data: A Case Study in MAXIMO CMMS2017Ingår i: Proceedings of MPMM 2016: 6th International Conference on Maintenance Performance Measurement and Management, 28 November 2016, Luleå, Sweden / [ed] Diego Galar, Dammika Seneviratne, Luleå: Luleå tekniska universitet, 2017, s. 105-110Konferensbidrag (Refereegranskat)
    Abstract [en]

    Computerised maintenance management systems (CMMS) are software packages; their data include information on an organisation’s maintenance, operations and costs. MAXIMO is recognised as a leading CMMS for asset management. It helps to manage maintenance data, improving data quality, making maintenance more efficient, and supporting decision making. However, MAXIMO systems have problems of data quality, with a resulting impact on efficiency and the validity of decisions based on those data. This paper investigates the quality of maintenance data in MAXIMO using the Swedish Transport Agency (Trafikverket) as a case study. It discusses the results before and after data cleaning to show the impact of data quality problems on data analysis.

  • 413.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hoseinie, Hadi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Monte Carlo Reliability Simulation of Underground Drilling Rigs2015Konferensbidrag (Refereegranskat)
  • 414.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hoseinie, Hadi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Monte Carlo Reliability Simulation of Underground Mining Drilling Rig2016Ingår i: Current Trends in Reliability, Availability, Maintainability and Safety: An Industry Perspective / [ed] Uday Kumar; Alireza Ahmadi; Ajit Kumar Verma; Prabhakar Varde, Encyclopedia of Global Archaeology/Springer Verlag, 2016, s. 633-643Konferensbidrag (Refereegranskat)
    Abstract [en]

    Drilling rigs are widely used in mine development or construction and tunnel engineering projects. The rig consists of 12 subsystems in a series configuration and can be driven by diesel or electrical engines. This paper uses the Kamat-Riley (K-R) event-based Monte Carlo simulation method to perform reliability analysis of an underground mine drilling rig. For data analysis and to increase statistical accuracy, the paper discusses three case studies in an underground mine in Sweden. Researchers built a process to programme the simulation process and used MATLABTM software to run simulations. The results showed the simulation approach is applicable to the reliability analysis of this rig. Moreover, the reliability of all rigs reaches almost zero value after 50 h of operation. Finally, the differences between the reliability of the studied fleet of drilling rigs are a maximum 10 %. Therefore, all maintenance or spare part planning issues can be managed in a similar way

  • 415.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Replacement team of mining drilling rigs2014Ingår i: Proceedings of Maintenance Performance Measurement and Management: th - 5th September 2014 Coimbra, Portugal : (MPMM 2014), 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a practical model to calculate the optimal replacement time (ORT) of drilling rigs used in underground mining. As a case study, cost data for drilling rig were collected over four years from a Swedish mine. The cost data include acquisition, operating, maintenance and downtime costs when using a redundant rig. A discount rate is used to determine the value of these costs over time. The study develops an optimisation model to identify the ORT of a mining drilling rig which represents a key performance indicator. It uses an artificial neural network (ANN) technique to identify the effect of the various cost factors on the ORT. The absolute ORT in the case study is 87 months, and there is an optimal replacement range within which the company can replace the rig. The results also show that the redundant rig cost has the largest impact on the ORT followed by acquisition, maintenance and operating costs. Regression analysis shows a linear relationship between the cost factors and the ORT of the drilling rig.

  • 416.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Al-Gburi, Majid
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Model for economic replacement time of mining production rigs including redundant rig costs2015Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 21, nr 2, s. 207-226Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose - This paper presents a practical model to determine the economic replacement time (ERT) of production machines. The objective is to minimise the total cost of capital equipment, where total cost includes acquisition, operating, maintenance costs and costs related to the machine’s downtime. The costs related to the machine’s downtime are represented by the costs of using a redundant machine. Design/methodology/approach - Four years of cost data are collected. Data is analysed, practical optimisation model is developed and regression analysis is done to estimate the drilling rigs ERT. The artificial neural network (ANN) technique is used to identify the effect of factors influencing the ERT of the drilling rigs.Findings - The results show that the redundant rig cost has the largest impact on ERT, followed by acquisition, maintenance and operating costs. The study also finds that increasing redundant costs per hour have a negative effect on ERT, while decreases in other costs have a positive effect. Regression analysis shows a linear relationship between the cost factors and ERT. Practical implications - The proposed approach can be used by the decision maker in determining the economic replacement time of production machines which used in mining industry.Originality/value - The research proposed in this paper provides and develops an optimisation model for economic replacement time of mining machines. This research also identifies and explains the factors that have the largest impact on the production machine’s ERT. This model for estimating the ERT has never been studied on mining drilling rigs.Keywords Decision support model, Life cycle cost, Optimisation, Replacement timePaper type Research paper

  • 417.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jonsson, Adam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Economic lifetime of a drilling machine: a case study on mining industry2013Ingår i: MPMM 2013 (Maintenance Performance Measurement and Management) / [ed] sari Monto; Miia Pirttilä; Timo Kärri, Lappeenranta, Finland: MPMM 2013 , 2013, s. 138-147Konferensbidrag (Refereegranskat)
    Abstract [en]

    Underground mines use many different types of machinery during the drift mining processesof drilling, charging, blasting, loading, scaling and bolting. Drilling machines play a criticalrole in the mineral extraction process and thus are important economically. However, as themachines age, their efficiency and effectiveness decrease, negatively affecting productivityand profitability and increasing total cost. Hence, the economic replacement lifetime of themachine is a key performance indicator. This paper introduces an optimisation model thatgives the optimal lifetime for a drilling machine. A case study has been done at anunderground Swedish mine to identify the economic replacement time of a drilling machine.It considers the purchase price, maintenance and operation costs, and the machine’s secondhandvalue. Findings show that the economic replacement lifetime of a drilling machine inthis mine is 96 months. The proposed model can be used for other underground miningmachines.

  • 418.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jonsson, Adam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Economic lifetime of a drilling machine: a case study on mining industry2015Ingår i: International Journal of Strategic Engineering Asset Management (IJSEAM), ISSN 1759-9733, E-ISSN 1759-9741, Vol. 2, nr 2, s. 177-189Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Underground mines use many different types of machinery duringthe drift mining processes of drilling, charging, blasting, loading, scaling andbolting. Drilling machines play a critical role in the mineral extraction processand thus are important economically. However, as the machines age, theirefficiency and effectiveness decrease, negatively affecting productivity andprofitability and increasing total cost. Hence, the economic replacementlifetime of the machine is a key performance indicator. This paper introducesan optimisation model that gives the optimal lifetime for a drilling machine. Acase study has been done at an underground Swedish mine to identify theeconomic replacement time of a drilling machine. It considers the purchaseprice, maintenance and operation costs, and the machine’s second-hand value.Findings show that the economic replacement lifetime of a drilling machine inthis mine is 96 months. The proposed model can be used for other undergroundmining machines.

  • 419.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jonsson, Adam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Case Study: Model for economic lifetime of drilling machines in the Swedish mining industry2015Ingår i: The Engineering Economist, ISSN 0013-791X, E-ISSN 1547-2701, Vol. 60, nr 2, s. 138-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this paper is to develop a practical economic replacement decision model to identify the economic lifetime of a mining drilling machine. A data driven optimisation model was developed for operating and maintenance costs, purchase price and machine resale value. Equivalent present value of these costs by using discount rate was considered. The proposed model shows that the absolute optimal replacement time (ORT) of a drilling machine used in one underground mine in Sweden is 115 months. Sensitivity and regression analysis show that the maintenance cost has the largest impact on the ORT of this machine. The proposed decision making model is applicable and useful and can be implemented within the mining industry.

  • 420.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Wijaya, Andi
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Downtime analysis of drilling machines and suggestions for improvements2014Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 20, nr 4, s. 306-332Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose– The purpose of this paper is to analyse and compare the downtime of four drilling machines used in two underground mines in Sweden. The downtime of these machines was compared to show what problems affect downtime and which strategies should be applied to reduce it.Design/methodology/approach– The study collects failure data from a two-year period for four drilling machines and performs reliability analysis. It also performs downtime analysis utilising a log-log diagram with a confidence interval.Findings– There are notable differences in the downtime of most of the studied components for all machines. The hoses and feeder have relatively high downtime. Depending on their downtime, the significant components can be ranked in three groups. The downtime of the studied components is due to reliability problems. The study suggests the need to improve the reliability of critical components to reduce the downtime of drilling machines.Originality/value– The method of analysing the downtime, identifying dominant factors and the interval estimation for the downtime, has never been studied on drilling machines. The research proposed in this paper provides a general method to link downtime analysis with potential component improvement. To increase the statistical accuracy; four case studies was performed in two different mines with completely different working environment and ore properties. Using the above method showed which components need to be improved and suggestions for improvement was proposed and will be implemented accordingly.

  • 421.
    Hamoudeh, Youssef
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Analysis of mine mobile fleet maintenance vs. mine roads maintenance for optimum performance2014Ingår i: Mine Planning and Equipment Selection: Proceedings of the 22nd MPES Conference, Dresden, Germany, 14th – 19th October 2013 / [ed] Carsten Drebenstedt; Raj Singhal, Cham: Encyclopedia of Global Archaeology/Springer Verlag, 2014, Vol. X, s. 1369-1380Konferensbidrag (Refereegranskat)
    Abstract [en]

    The expansion of the mining operations world-wide leads to development of large vehicles. In the past the design of the mine haul roads was done empirically based on the local experience; this way is not applicable anymore because the extreme increase of the truck sizes which demands more focus on mine haul roads quality and performance. The inadequate designs will not only increase the mine haul road maintenance but also will increase the overall operating and maintenance costs of the vehicles. Therefore it is necessary to improve the designs and quality for the mine haul road. The aim of this study is to find out the optimum points which indicate the minimum maintenance cost for both transportation machineries and mine haul roads for both surface and underground mines. The parameters which considered for the transportation machineries are tires consumption, parts vehicles consumption, and labour hour maintenance costs. The major problems in the mine haul roads and vehicles are discussed. The maintenance and rehabilitation of the pavements deterioration are also considered with respects to their costs besides to the minimum accepted values for the pavements performance levels. Consequently, the achievements will comprise minimizing the operation costs, and optimizing the availability and performance/capacity of mobile fleet.

  • 422.
    Hamstig, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Yngman, Malin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Analys av underhållsprocessen för truckdäck i Aitikgruvan: Nulägesbeskrivning och RAMS-analys2016Självständigt arbete på grundnivå (högskoleexamen), 180 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Boliden Mineral AB är ett metallföretag som producerar metaller för det moderna samhället.

    Företaget har två dagbrottsgruvor belägna i Aitik strax utanför Gällivare i norra Sverige, varav

    en är landets största dagbrott. Stora gruvtruckar av två olika modeller transporterar malm från

    gruvan till anrikningsverket där koppar och andra metaller utvinns. Truckarna utgör en viktig del

    av logistiken som influerar den totala produktiviteten i verksamheten. Skadade truckdäck har

    visat sig vara en av de största orsakerna till tillgänglighetsförluster för truckarna. Studiens syfte

    var att skapa en nulägesbeskrivning gällande underhållskedjan av skadade truckdäck i företaget

    samt ge förslag på förändringar av däckunderhållet för att förbättra tillgängligheten på truckarna

    genom att minska nedtiden för däckskador. Intervjuer med inblandade personalgrupper i

    underhållskedjan samt analyser av underhållsdata ligger till grund för resultatet i studien. En

    RAMS-analys utfördes för att finna felorsaker i underhållskedjan som bidrar till lägre

    driftsäkerhet av gruvtruckarna med avseende på däckskador.

    RAMS-analysen påvisade att de flesta flaskhalsarna i underhållskedjan finns inom området

    underhållssäkerhet, vilket innebär att underhållsorganisationen reagerar för långsamt för att

    underhållet ska kunna bedrivas optimalt. Däckunderhållet tar generellt för lång tid i förhållande

    till de ideala feltider som vore möjliga att uppnå för båda truckmodellerna. Tillräcklig utbildning

    för att bedömma skadade truckdäck saknas stora delar av dygnet, resursbrist kan förekomma i

    truckverkstaden samt otydliga direktiv råder mellan arbetsgrupper hur kommunikationen skall

    förmedlas vilket förlänger nedtiderna. I syfte att optimera underhållssäkerheten bör tydliga

    rutiner mellan arbetsgrupperna skapas, vidare bör utbildningen utökas till berörda arbetsgrupper

    vilket innebär att bedömning av däckskador kan ske oavsett tid på dygnet. Arbetsfördelningen

    för de inblandade arbetsgrupperna bör omfördelas för att skapa en mer effektiv underhållskedja.

    Utifrån funktionssäkerheten visade studien att den nyare truckmodellen har större problem med

    däckskador än den äldre truckmodellen. Av de truckdäck där drifttiden analyserats visade sig ett

    av däckmärkena ha för korta drifttider jämfört med Bolidens internt uppsatta gränsvärden.

    Underhållsmässigheten visade att den nyare truckmodellen är svårare att underhålla eftersom

    komponenterna är större samt att utrustning saknas för att utföra fler än ett däckbyte samtidigt. I

    övrigt har Boliden två olika avtal gällande däck och studien presenterar förändringar i dessa

    som möjliggör att företaget ska kunna höja tillgängligheten. För att kunna göra bättre

    kartläggningar och analyser om underhållskedjan utifrån underhållsdata kring däckskador på

    truckarna bör företaget skapa bättre rutiner för inrapportering och dokumentation.

  • 423.
    Hassabelnaby, Aly
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Development of a maintenance plan for the STEPWISE project at Swerea MEFOS2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Process plants come with a wide variety of engineering challenges. Each process has uniqueoperating conditions that require careful operation and maintenance programs to keep the process equipment in a condition that is safe for operation. A pilot-scale plant was built in Luleå to demonstrate the possibility of carbon dioxide removal from blast furnace gas usingthe Sorption Enhanced Water Gas Shift (SEWGS) technology. One of the challenges facingthe SEWGS pilot plant was the lack of a maintenance plan which was the motivation for this thesis.

    The aim of this thesis was to create a maintenance plan for the SEWGS pilot plant. Studying the process conditions of the pilot plant was the starting point since an understanding of the unique operating conditions was necessary for creating a maintenance plan for the pilot plant’s equipment.

    The Reliability-centered maintenance (RCM) method was chosen to create the maintenance plan. The study began with determining the objectives and contents of the analysis. The next step was a functional failure analysis in the form of a Failure Mode and Effect Criticality Analysis (FMECA) covering all the equipment in the plant. Afterwards the failure consequences were assessed based on a criticality assessment matrix to determine which equipment necessitate the performance of maintenance activities.

    The maintenance plan was created based upon the criticality of the equipment and the selected maintenance activities were based on the recommendations of manufacturers. The failure analysis found that the blast furnace gas compressor is the most critical for the process. The boiler and superheater have been found to be highly critical due to the dangerous safety consequences of their failure.

    In addition, all pressure safety valves have been found to be highly critical due to the hidden nature of their failure. The maintenance plan addresses these critical items and other less critical items while some non-critical items have been removed from the plan due to the negligible consequences of their failure.

  • 424.
    Hassan, Syed Alley
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Transition from surface to underground mining in the Arctic region: A case study from Svartliden Gold Mine, Sweden.2014Ingår i: Mine Planning and Equipment Selection: Proceedings of the 22nd MPES Conference, Dresden, Germany, 14th – 19th October 2013 / [ed] Carsten Drebenstedt; Raj Singhal, Germany: Encyclopedia of Global Archaeology/Springer Verlag, 2014, Vol. X, s. 1397-1408Konferensbidrag (Refereegranskat)
    Abstract [en]

    Gold ores often consist of nuggets associated with quartz veins. In other ore types gold can be found as a by-product to pyrite. For both types, mine planning of scattered veins type deposits is often complicated regarding both mine design and production scheduling. Despite the cold climate in the Arctic region, near surface deposits are initially mined with open pit mining. As the mine goes deeper, the stripping ratio and the transportation cost increases which economically limit the possibility to continue the project with open pit mining. The transition to underground mining, with gradually decreasing production from an open pit, near its final depth, and with gradually increasing production from newly developed underground production areas, require detailed planning and production scheduling to avoid production delays and maintaining a high cash flow. This paper high-lights the main operational aspects of the Svartliden gold mine in Sweden and in particular how a scattered gold deposit during harsh cold weather conditions was dealt with. The on-going transition from surface to underground mining and the applied concept of minimizing own personnel in favour of national and local contractors for production purposes are also discussed.

  • 425.
    Haupt, Dan
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Nord, Kent
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Tingvall, Bror
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahlvik, Peter
    Ecotraffic ERD3 AB.
    Egebäck, Karl-Erik
    Autoemission KE E Concultant.
    Andersson, Sören
    STT EMTEC.
    Blomquist, Micael
    STT EMTEC.
    Investigating the potential to obtain low emissions from a diesel engine running on ethanol and equipped with EGR, catalyst and DPF2004Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Experiments were performed to investigate the potential to achieve low emissions from a diesel engine fueled by ethanol and equipped with a commercially available exhaust after-treatment device, DNO\dx\sT from STT Emtec. The DNO\dx\sT system includes exhaust gas recirculation (EGR) catalysts and a continuously regenerating diesel particulate filter (DPF). Two Euro III classified 9-liter turbocharged, after-cooled diesel engines from Scania were used for the task. One engine was fueled by ethanol and the other by Swedish diesel fuel, EC1. Engine operating conditions of a 22-mode test cycle, including the 13 modes of the European Stationary Cycle (ESC cycle), were used for the tests. The emissions of NO\dx and HC were small for the ethanol-fueled engine, 3.48 and 0.53 g/kWh, respectively, while the emission of CO was higher, 2.07 g/kWh. Estimations of emitted particle mass were calculated by using the software supplied in the Scanning Mobility Particle Sizer (SMPS). The estimations showed that the ethanol engine emitted only \mA1/10 of the particle mass emitted by the diesel-fueled engine. A powerful reduction of the regulated emissions was obtained when equipping the ethanol engine with EGR, catalyst and DPF. The emissions of HC, CO and NO\dx decreased down to 0.15, 0.04 and 2.54 g/kWh, respectively, while the estimated particle mass was reduced by 67%. Actually, by using the aftertreatment system, the engine became a Euro IV engine regarding the emissions of HC, CO and NO\dx. The system worked even better with the diesel-fueled engine. The NO\dx emission was reduced by approximately 33% and the estimated particle mass by more than 99%. Calculations showed that the EGR ratio was higher for the diesel engine than for the ethanol engine. Consequently, by applying a higher EGR ratio for the ethanol engine an additional reduction of the NO\dx emissions should be obtained. The results indicate that very low NO\dx and particle emissions could be obtained for an ethanol-fueled diesel engine by using the right aftertreatment equipment. Future studies should investigate the possibility to increase the EGR ratio further. The investigations also underline the need for development of a special particulate filter for ethanol engines.

  • 426.
    Hernandez, Angel
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Techniques of Prognostics for Condition-Based Maintenance in Different Types of Assets2014Rapport (Refereegranskat)
  • 427.
    Hernandez, Angel
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Perales, Numan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Procedure for rul estimation in industrial assets2014Ingår i: Proceedings of the 3rd international workshop and congress on eMaintenance: June 17-18 Luleå, Sweden : eMaintenance, Trends in technologies & methodologies, challenges, possibilites and applications / [ed] Uday Kumar; Ramin Karim; Aditya Parida; Philip Tretten, Luleå: Luleå tekniska universitet, 2014, s. 145-149Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today, prognosis is recognized as a key element of maintenance.However, the implementation of an efficient prognosis tool can becomplicated in industrial and academic sectors, when we speakabout academic sector , we refer to the research centers atuniversities who study the progress and new technologies relatedto prognosis, these centers are very important as they help theimprove maintenance management in the industries. Since it isdifficult to create effective models for different industrial assets.In this context, our general objective is to propose a procedure forimplementing prognosis, from selecting the system or componentto be analyzed to obtaining the estimation of the remaining usefullife. We also explain different approaches to forecasting toestimate remaining useful life, the main objective of prognosis.

  • 428.
    Holgerson, Mikael
    et al.
    Luleå tekniska universitet.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Engagement behaviour of a paper-based wet clutch: Part 1: Influence of drive torque1999Ingår i: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991, Vol. 213, nr 4, s. 341-348Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Owing to increasing demands when designing wet clutches for automatic transmissions, more knowledge about their behaviour is needed. In cars with power shifting automatic transmissions, an engine torque is continuously transmitted through the gear box. Most experimental and theoretical work concerning investigations of wet clutches today uses the inertia type of test apparatus, e.g. the SAE test machine 2. However, this type of test machine has no possibility of investigating the influence of a drive torque from the power supply. In order to investigate the influence of drive torque on wet clutch engagements, a new type of apparatus was built, which can operate with different combinations of inertia and drive torque. This apparatus can perform engagements more similar to those in automatic transmissions. The aim of this paper was to compare experimental outputs obtained using these principles of testing, concerning the influence of drive torque. It was found that the friction characteristics of wet clutches are independent of how the input energy is produced. This means that friction can be investigated with both principles. It was also found that an apparatus using only inertia gives shorter engagement times and higher temperatures than an apparatus including a drive torque at the same level of input energy. This can be explained by different power characteristics. Therefore, when investigating temperatures of wet clutch engagements, one must be careful when translating the results into reality.

  • 429.
    Holgerson, Mikael
    et al.
    Luleå tekniska universitet.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Engagement behaviour of a paper-based wet clutch: Part 2: Influence of temperature1999Ingår i: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991, Vol. 213, nr 5, s. 449-455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To increase comfort, performance and fuel economy, a more careful optimization of automatic transmissions is needed. Of special interest is how the temperature influences the engagement characteristics. In order to increase the level of knowledge in this area, a wet clutch test rig including a drive torque and inertia was used. The temperature and the developed energy were varied in order to investigate their influence on the characteristics of an engagement. As a consequence the influence of instant temperature, maximum temperature and instant normal force was also studied. Some of the most important conclusions of the investigation are that both the dynamic and static friction coefficients slightly decrease and the engagement time increases with increasing temperature. It was also found that the static and dynamic friction coefficients are not influenced by energy if the instant temperature is the same. An important parameter that describes the risk of stick-slip is the quotient between the static and dynamic friction. It was found that this quotient decreases with increasing temperature, and thus the risk of stick-slip is also supposed to decrease.

  • 430.
    Holmgren, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Maintenance related losses: a study at the Swedish National Rail Administration2003Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Den globala konkurrensen ställer allt högre krav på driftsäkerhet och säkerhet hos produktionssystemen. Den normala driften av systemet leder till en gradvis försämring av dess status p.g.a. slitage, smuts, korrosion och överbelastning. Utförande av underhåll är ett sätt att säkerställa systemets driftsäkerhet och säkerhet. Även om underhåll genomförs för att öka säkerheten kan dock felaktigt eller uteblivet utfört underhåll reducera systemets säkerhet och skapa förluster genom incidenter och olyckor.Syftet med denna studie är att identifiera, klassificera och analysera underhållsrelaterade incidenter och olyckor. Resultatet ska kunna användas för att bättre styra underhållsentreprenader och därigenom säkerställa säkerheten för passagerare och personal vid Banverket och därigenom vara en del av deras ständiga förbättringsarbete. För att uppfylla syftet har en databasstudie och en litteraturstudie genomförts. Databasstudien fokuserades på incidenter och olyckor vid den Svenska järnvägen. Studiens resultat kan delas upp i två delar. Den första delen är en analysmodell, som används för databasstudien. Denna modell beskriver orsakskedjan från bristande styrning till förluster, vilka manifesteras i incidenter och olyckor. Den andra delen, vilken baseras på empiri, är en klassificering av incidenter och olyckor vid den Svenska järnvägen. Underhållsrelaterade incidenter och olyckor klassificeras och analyseras. De primära orsakerna till dessa incidenter och olyckor bestäms och diskuteras. Ungefär 30% av de spårrelaterade incidenterna och olyckorna orsakas av bristfälligt utfört underhåll. Andra bidragande orsaker är bristande kommunikation och regelbrott.

  • 431.
    Holmgren, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Maintenance related risks: Do they need any further investigation2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    The purpose of maintenance is to ensure safety and dependability of a system. The maintenance personnel perform different maintenance activities. In Sweden there exist regulations, to some extent covering maintenance and operation of technical systems. The purpose of these regulations is to reduce the risk for the humans, the environment and the property. Still, many accidents occur in connection with maintenance or service. Reasons for this are, e.g., that procedures are not followed, proper training is lacking, or the maintainability of the system is poor.In an ongoing study at the Centre for Dependability and Maintenance at Luleå University of Technology, a number of company representatives are interviewed and incident reports and accident investigations from a number of different papers and scientific reports are studied with respect to possible maintenance related causes and corresponding effects. The purpose of this study is to perform an investigation in order to answer the question: Do maintenance related risks need further investigation? In this paper some preliminary findings will be presented.

  • 432.
    Holmgren, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Maintenance-related incidents and accidents: aspects of hazard identification2006Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The satisfaction of stakeholders depends upon the fulfilment of their requirements. Two important stakeholder requirements related to technical systems are dependability and safety. However, system operation will gradually impair its performance leading to potentially hazardous states of the system. Maintenance is all activities aimed at retaining a system in, or restoring it to, a state where it can fulfil the stakeholders’ requirements. However, although maintenance is performed in order to ensure dependability and safety, incorrectly performed maintenance may contribute to accidents with extensive losses. Traditionally, human failures have often been appointed as one major cause of these maintenance-related accidents. However, human failures are not completely satisfactory as an explanation for incidents and accidents since there most often are other contributory causes to these failures. The purpose of this thesis is to explore and describe hazards contributory to maintenance-related incidents and accidents, in order to support continuous risk reduction. To fulfil the stated purpose, two case studies, supported by a literature study, have been performed. One case study focused on documented maintenance-related incidents and accidents within the Swedish railway. The second case study focused on perceived hazards in relation to maintenance execution within the Swedish paper industry. The railway case study indicates that improper infrastructure maintenance is a major cause of collisions and derailments within the Swedish railway. Furthermore, the study indicates that the three major maintenance-related hazards within the Swedish railway system are: communication errors, information retrieval errors and omitted operations. The study also proposes that it is not good enough to accept human failures, i.e. human error or rule violation, as a root cause of maintenance-related incidents and accidents. Both case studies show that a major maintenance-related hazard is insufficient communication between different activities associated with maintenance execution. Another common finding from the studies is that incidents manifested during maintenance execution might be caused by hazards in other maintenance-related activities within the maintenance process. In addition, both case studies show that a proposed process model of maintenance is a valuable support in hazard identification.

  • 433.
    Holmgren, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Maintenance-related losses at the Swedish rail2005Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 11, nr 1, s. 5-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose - The purpose of this study is to identify maintenance related losses, and their causes, in order to describe different deviations in the maintenance process that contributes to incidents and accidents at the Swedish Railway. Design/methodology/approach - In this paper incident and accident reports from 666 derailments and collisions at the Swedish Railway during 1988-2000, stored in a national database, are studied with respect to possible maintenance related causes. Findings - The railway is a complex technical system used for both freight and passenger transportation. Maintenance is one way to achieve safety and dependability of the railway. However, at the same time badly performed maintenance may also cause accidents. The study shows that maintenance related causes represent 30 percent of all rail and track related incidents and accidents represented in the database. About 80 percent of the maintenance related accidents happen during the execution phase. The most common cause of maintenance related accidents is imperfect communication and information between the maintenance personnel and the operators. Rule violations, especially lack of permission to perform maintenance work on the track, are the second most frequent causes. Originality/value - Identifies maintenance related losses, and their causes, on Swedish railways but is of value to all concerned with transport maintenance and safety.

  • 434.
    Holmgren, Mattias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Akersten, Per-Anders
    The maintenance process: looked upon through risk glasses2002Ingår i: Proceedings of the 16th European Maintenance Congress: Euromaintenance 2002, 2002, s. 267-273Konferensbidrag (Refereegranskat)
  • 435.
    Holmgren, Mattias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    A process approach to maintenance-related hazard identification2008Ingår i: International Journal of COMADEM, ISSN 1363-7681, Vol. 11, nr 1, s. 36-46Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    History has shown that maintenance contributes to incidents and accidents with extensive losses. The purpose of this paper is to describe a process approach for maintenance-related hazard identification, in order to support continuous risk reduction in maintenance activities. The proposed maintenance process model has been applied within a study of maintenance execution of DC-motors in paper-mills. However, both the model and the findings from its application are believed to be transferable to the maintenance of other critical technical systems. A recurring hazard is insufficient feedback. Hence, proper feedback may help to reduce risk. Further findings indicate that incidents manifested during execution may be due to hazards in other process phases. The maintenance of complex and critical systems is also affected by the work environment and knowledge of technicians, whose requirements should be fulfilled through appropriate organisational and technical support.

  • 436.
    Holmgren, Mattias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Söderholm, Peter
    Trafikverket, Luleå.
    Process Analysis of Human Failures in Railway Maintenance2016Ingår i: Current Trends in Reliability, Availability, Maintainability and Safety: An Industry Perspective / [ed] Uday Kumar; Alireza Ahmadi; Ajit Kumar Verma; Prabhakar Varde, Encyclopedia of Global Archaeology/Springer Verlag, 2016, s. 381-393Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of maintenance is to retain and restore the required functions of technical systems to ensure the productivity and efficiency of technical systems. However, improper maintenance, in the sense of incorrectly performed maintenance or lack of suitable maintenance activities, contributes to deterioration and, even more seriously, cause incidents and accidents. Therefore, it is important to identify hazards from occurred incidents and accidents to learn and avoid these hazards in the future. For that matter, in turn, documentation from occurred events should be done in a systematic way and then be an important part of the management system—and last, but not least, used for continuous improvement and risk reduction. This study aims to describe a process-oriented approach to analyse causes of human failures contributory to maintenance-related incidents and accidents, in order to support continuous risk reduction. The proposed methodology with supporting tools can be used for analysis purposes and guide decision making. The approach is illustrated by a case study at the Swedish railways

  • 437.
    Horenbeek, Adriaan Van
    et al.
    Centre for Industrial management, KU Leuven.
    Pintelon, Liliane
    Centre for Industrial management, KU Leuven.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Integration of disparate data sources to perform maintenance prognosis and optimal decision making2012Ingår i: The Ninth International Conference on Condition Monitoring and Machinery Failure Prevention Technologies, 2012, Vol. 1, s. 386-397Konferensbidrag (Refereegranskat)
    Abstract [en]

    Prognosis can be defined as the course of predicting a failure of equipment or a component in advance, whereas prognostication refers to the act of prediction. The three main branches of condition based maintenance are diagnosis, prognosis, and treatment-prognosis, however prognosis is admittedly the most difficult. Also, this area has been the least described in literature and the knowledge about it in a maintenance management context is still poorly systematized. To this day, formal professional attention to prognosis, in the field of maintenance management and engineering in the everyday care of machinery, is often relegated to a secondary status although the availability of prognostic information can considerably improve (e.g. reduce costs, maximize uptime) the performance of machinery and maintenance processes. Ideally, assessment of a prognosis of remaining useful life should be deliberate and explicit. In order to support the maintenance crew in the achievement of this objective an increasing amount of prognostic information is available. Over the last decade, system integration has grown in popularity as it allows organizations to streamline business processes. It is necessary to integrate management data from CMMS (Computer Maintenance Management Systems) with CM (Condition Monitoring) systems and finally SCADA (Supervisory Control And Data Acquisition) and other control systems, widely used in production but with a seldom usage in asset diagnosis and prognosis. The most obvious obstacle in the integration of these data is the disparate nature of the data types involved, moreover several attempts to remedy this problem have fizzled out. Although there have been many recent efforts to collect and maintain large repositories of these types of data, there have been relatively few studies to identify the ways these datasets could be related and linked for prognosis and maintenance decision making. After identifying what and how to predict incipient failures and developing a corresponding prognosis, maintenance engineers must consider how to communicate the prediction. In this activity once again, technicians' psychosocial attributes and values may influence how they discuss prognoses with asset managers. Regardless of whether prognostic assessments are subjective or objective, however, technicians should consider two major points. Firstly, the maintenance crew should clarify in their own minds the link, if any, between their prognostic assessment and their consequent decision making. Secondly, they should consider the ways that they and their assets might benefit from explicitly discussing how the prognostic assessment is linked with diagnostics and preventive maintenance recommendations. These and other steps that maintenance engineers should take in incorporating prognostic information into their decision making are discussed in this paper. The objective is to give an overview of how the integration of disparate data sources, commonly available in industry, can be achieved for maintenance prognosis and optimal decision making.

  • 438.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. Faculty of Mining Engineering and Geophysics, Shahrood University of Technology.
    Aghababaei, H.
    Faculty of Mining Engineering, Sahand University of Technology, Tabriz.
    Pourrahimian, Y.
    Faculty of Mining Engineering, Sahand University of Technology, Tabriz.
    Development of a new classification system for assessing of rock mass drillability index (RDi)2008Ingår i: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 45, nr 1, s. 1-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The drilling process and its results are affected by various parameters of the rock material and rock mass. The effects of rock material have been emphasized in various studies; however lack of perfect knowledge of rock mass structural parameters may lead to unpredictable results. This paper presents a new classification system for specifying the rock mass drillability index (RDi). For this purpose, six parameters of the rock mass, including texture and grain size, Mohs hardness, uniaxial compressive strength (UCS), joint spacing, joint filling (aperture) and joint dipping have been investigated by physical modeling and rated. Physical modeling in particular has been used for investigating the effects of joint characteristics on drilling rate. In the proposed RDi system, each rock mass is assigned a rating from 7 to 100, with a higher rating corresponding greater ease of drilling. Based on the RDi rating, the drilling rate may be classified into five modes: slow, slow-medium, medium, medium-fast, and fast.

  • 439.
    Hoseinie, Hadi
    et al.
    Hamedan University of Technology.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability-centered maintenance for spray jets of coal shearer machine2013Ingår i: International Journal of Reliability, Quality and Safety Engineering (IJRQSE), ISSN 0218-5393, Vol. 20, nr 3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Spray jets constitute one of the most important parts of each type of rock cutting machine, especially the drum shearer. This system cools the cutting picks and controls the dust emission. The blockage of spray jets causes the coal shearer machine to stop automatically. Therefore, the reliable performance of this system assists the achievement of a smooth coal cutting operation. Field's data shows that the maintenance of this system is time-consuming and causes major downtimes in the production process. Therefore, it is essential to find an optimum preventive maintenance task and intervals, to reduce the downtime and minimize the associated costs of the machine. The aim of this paper is to identify an applicable and effective maintenance task, with its associated interval, for management of the failure modes of the spray jets of coal shearers. A case study has been conducted on spray jets of double-drum shearer machine in Tabas Coal Mine in Iran. In the study, the RCM approach is used to select an applicable and effective maintenance task. The failure data were analyzed using a parametric approach to evaluate the reliability of the spray jets, and to estimate the reliability parameters. A reliability-based cost modeling has been implemented to identify the optimum maintenance interval and frequencies of restoration for the spray jets. In the study, a cost rate function (CRF) has been introduced in which an as-good-as-new (AGAN) effectiveness for restoration actions is considered. The CRF also considers restoration and repair times, and takes into account the costs associated with repair and restoration, and the opportunity cost of the equipment's lost production due to maintenance downtime, to arrive at the most cost-effective maintenance intervals. The results of the analysis have shown that the minimum cost per unit of time, $46.5/h, will be achieved within a range of intervals i.e., T = 210 h to T = 260 h.

  • 440.
    Hoseinie, Hadi
    et al.
    Faculty of Mining Engineering, Hamedan University of Technology.
    Ataei, Mohammad
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology.
    Khalokakaie, Reza
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability analysis of drum shearer machine at mechanized longwall mines2012Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 18, nr 1, s. 98-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose - Longwall mining is a special mining method with high productivity and smooth operation and the drum shearer is known as the most important component in longwall mines due to its direct role in the coal cutting and production process. Therefore, its reliability is important in keeping the mine production at a desired level. Hence, reliability analysis is essential in identifying and removing existing problems of this machine in order to achieve a better production condition. This paper seeks to learn about the reliability of the shearer machine in order to locate critical subsystems. The improvement of the reliability of the critical subsystems, to enhance the optimum operation of the shearer machine, is the main objective of this research. Design/methodology/approach - A basic methodology was used in this paper for the reliability modeling of the shearer machine. First, failure and performance data from a two-year period at the Tabas Coal Mine-Iran was classified and sorted. The tests for validating the assumption of independent and identical distribution (iid) of TBF data are done and the best modeling method for each subsystem was selected among the renewal process, homogeneous Poisson process and non-homogeneous Poisson process. Finally, the reliability of subsystems and the machine were assessed. Findings - The study revealed that six important subsystems of the shearer machine are; water system, haulage, electrical system, hydraulic system, cutting arms, and cable system. Pareto analysis shows that the 30 percent of failures and stoppages of the shearer were related to the water system and this system is the most critical subsystem of the machine. The failure rate analysis shows that the failure rates of the hydraulic, haulage and electrical systems were decreasing, meanwhile, the failure rates of the water system, cutting arms and cable system were increasing. The reliability of drum shearer reaches the zero value after 100 hours. Originality/value - This paper, for the first time, defines a practical set of subsystems for the coal shearer based on field data and machine design

  • 441.
    Hoseinie, Hadi
    et al.
    Shahrood University of Technology.
    Ataei, Mohammad
    Shahrood University of Technology.
    Khalokakaie, Reza
    Shahrood University of Technology.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability analysis of cable system of drum shearer using power law process model2012Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 26, nr 4, s. 309-323Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article, the reliability of the cable system of a drum shearer machine was studied and analysed using operation and maintenance data from an Iranian mine for a period of two years. The tests for trend and serial correlation show that the times between successive failures for the cable system are not independent and identically distributed. A goodness-of-fit test shows that the power law process model provides a good fit to the failure data of this system. After parameter estimation for the power law model, reliability and failure rate plots were obtained. Based on analysis and results, a period of 125 h was defined as the reliability-based maintenance interval for the cable system of the shearer. The analysis shows that, by using this strategy, the reliability of the system will improve by at least 50%.

  • 442.
    Hoseinie, Hadi
    et al.
    Shahrood University of Technology.
    Ataei, Mohammad
    Shahrood University of Technology.
    Khalokakaie, Reza
    Shahrood University of Technology.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability modeling of water system of longwall shearer machine2011Ingår i: Archives of Mining Sciences, ISSN 0860-7001, E-ISSN 1689-0469, Vol. 56, nr 2, s. 291-302Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In cutting machines of mining and construction works, water system has an important and critical role. Due to many aspects and reasons, these machines can not work without water. In longwall mining, the drum shearer performance is highly related to its water system. Any problem in water system of shearer leads the machine to stop automatically; therefore, the reliability of this system is very important in reliability of shearer. In this study, for modeling this system, three subsystems in series network were considered; filters, spray jets and hoses & valves. Then, the field data of water system of drum shearer of Tabas Coal Mine has been collected and analyzed using statistical modeling technique. The results showed that filters subsystem has the highest reliability importance among the subsystems and is defined as the most critical subsystem. In addition, the filters, spray jets and hoses reach the reliability of 80% respectively after about 8.5, 23 and 87 hours.

  • 443.
    Hoseinie, Hadi
    et al.
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology.
    Ataie, Mohammad
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology.
    Khalookakaei, Reza
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability modeling of hydraulic system of drum shearer machine2011Ingår i: Journal of Coal Science and Engineering (China), ISSN 1006-9097, E-ISSN 1866-6566, Vol. 17, nr 4, s. 450-456Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The hydraulic system plays an important role in supplying power and its transition to other working parts of a coal shearer machine. In this paper, the reliability of the hydraulic system of a drum shearer was analyzed. A case study was done in the Tabas Coal Mine in Iran for failure data collection. The results of the statistical analysis show that the time between failures (TBF) data of this system followed the 3-parameters Weibull distribution. There is about a 54% chance that the hydraulic system of the drum shearer will not fail for the first 50 h of operation. The developed model shows that the reliability of the hydraulic system reduces to a zero value after approximately 1 650 hours of operation. The failure rate of this system decreases when time increases. Therefore, corrective maintenance (run-to-failure) was selected as the best maintenance strategy for it

  • 444.
    Hoseinie, Hadi
    et al.
    Department of Mining Engineering, Isfahan University of Technology.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Bagherpour, Raheb
    Department of Mining Engineering, Isfahan University of Technology.
    Failure mode and effect analysis (FEMA) in automated mining machinery2017Ingår i: Mine Planning and Equipment Selection (MPES 2017): Proceeding of the 26th International Symposium on Mine Planning and Equipment Selection Luleå, Sweden, August 29-31, 2017 / [ed] Behzad Ghodrati, Uday Kumar, Håkan Schunnesson, Luleå: Luleå tekniska universitet, 2017, s. 81-86Konferensbidrag (Refereegranskat)
  • 445.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Juuso, Esko
    University of Oulu, Control Engineering Group, Faculty of Technology, University of Oulu.
    Optimal Preventive Maintenance Planning for Water Spray System of Drum Shearer2015Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water spray system is one of the most important parts of rock cutting machines, especially the drum shearer. Field data shows that the maintenance of this system is time-consuming and causes major downtimes in the coal mines’ production process. Therefore, it is essential to find an optimum preventive maintenance task and intervals, to reduce the downtime and minimize the associated costs of the machine. In this paper, in order to suggest an optimum preventive maintenance plan, a parametric failure and reliability analysis was done on available data from an Iranian longwall coal mine over the two years. A reliability-based cost modelling was implemented to identify the optimum maintenance interval and frequencies of restoration for the water spray system. In the study, a cost rate function was introduced in which an as-good-as-new effectiveness for restoration actions is considered. The results of the analysis showed that the minimum maintenance cost per unit of time for the studied machine, $19.54/hour, will be achieved within a range of intervals i.e. T=136 hours to T=142 hours.

  • 446.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hosseini, A.
    Iran Minerals Production and Supply Co., Tabas Parvadeh Coal Company, Tabas.
    Availability analysis of drum shearer machine;: A Case Study2015Ingår i: Proceedings of the 24th International Mining Congress of Turkey, IMCET 2015: Antalya, Turkey, 14- 17 April 2015 / [ed] M. Karadeniz, TMMOB Maden Muhendisleri Odasi , 2015, s. 913-918Konferensbidrag (Refereegranskat)
    Abstract [en]

    Drum shearer plays an important role in the face production in longwall coal mines. Therefore, monitoring of this machine can lead the whole extraction operation to high level of productivity and safety. Availability is one of the most important measures for evaluation of the mining machineries. High availability of equipment can be helpful in satisfying the desired production goals. In this article the availability of drum shearer in an Iranian coal mine has been studied. For this purpose, the failure and maintenance data for a period of two years have been used. After data sorting and analysis, the inherent availability, achieved and operational availability of this machine have been calculated. The results show that the studied shearer machine performs in high level of availability. Nevertheless, the logistics delay time and administrative delays with the share of 25% of whole downtimes are so important influencing factors which should be controlled and planned to minimize it.

  • 447.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Assessment of Reliability-Related Measures for Drum Shearer Machine: a Case Study2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Longwall mining is one of the most continuous and productive mining methods. Efficiency of this method is directly affected by the involved machineries and systems. The drum shearer plays an important role in the face productivity and the mine life. Therefore, monitoring of this machine can lead the whole extraction operation to a high level of production and safety. There are several reliability-related measures for evaluation of the mining equipment. Availability, utilization, production efficiency and overall production effectiveness are the most important measure which can help us in this way. In this paper, the production and failure data of a drum shearer machine in Parvade coal mine in Iran have been collected from whole of one longwall panel during a two-year period. The mentioned reliability-related measures have been calculated based on the total uptime and downtime of the machine. The results showed that, the studied drum shearer is in good availability level. However, it has average production efficiency, very low utilization and very low overall equipment effectiveness. Also, high waiting and idling time raises from other machineries during the extraction process, was recognized as the main reason for the current low productivity of shearer machine in mine.

  • 448.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Cost-effective maintenance scheduling of cutting arms of drum shearer machine2014Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 28, nr 5, s. 297-310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cutting arms are the main productive units of coal shearer machine that contact directly with coal seam. More importantly, the cutting arms operate under a high-stressed environment. In this paper, in order to suggest an optimum maintenance plan for the subsystem of shearer machine, firstly, we conducted a failure and reliability analysis using the data acquired from the Parvade coal mine, Iran over the two years. The analysis shows that the Power Law Process model provides a good fit to the failure data. Also, we applied estimated distribution functions and calculated cost parameters to identify the cost-based optimum preventive maintenance interval. Furthermore, we conducted a sensitivity analysis of the studied machine and identified that if we consider the variation of the world price of the raw coal then the maintenance plan is sensitive to the price. The analysis showed that, big changes in world price of raw coal are not so effective on maintenance plan but have a considerable effect on maintenance costs of the cutting arms of the shearer machine. However, the effects of this change on reliability improvement are almost zero.

  • 449.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Maintenance planning for drum shearer machine based on its reliability characteristics and economical sensitivity analysis2015Ingår i: Safety and Reliability: Methodology and Applications / [ed] Tomasz Nowakowski; Marek Mlynczak; Anna Jodejko-Pietruczuk ; Sylwia Werbinska-Wojciechowska, London: CRC Press, 2015, s. 1257-1262Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cutting arms are the main productive units of coal shearer machine that contact directly with coal seam. More importantly, the cutting arms operate under a high stress environment. In this paper, in order to suggest an optimum maintenance plan for the subsystem of shearer machine, firstly, we conducted a failure and reliability analysis using the data acquired from the Parvadeh coal mine Iran over the last two years. In doing so, we applied estimated distribution functions and calculated cost parameters to identify the cost-based optimum preventive maintenance interval. The analysis shows that the Power Law Process model provides a good fit to the failure data. Accordingly, the preventive maintenance operation can improve the reliability of the system by 53.5%. Furthermore, we conducted a sensitivity analysis of the studied machine and identified that if we consider the variation of the world price of the raw coal then the maintenance plan is sensitive to the price, however the effects of this change on reliability improvement is almost zero

  • 450.
    Hoseinie, Hadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Monte Carlo reliaility simulation of water system of longwall shearer machine2013Ingår i: International Journal of Reliability, Quality and Safety Engineering (IJRQSE), ISSN 0218-5393, Vol. 20, nr 6, artikel-id 1350023Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The water system of coal shearer machine consists of three main subsystems namely spray jets, water & hoses, and filters which are connected and working in series configuration. In this paper the Kamat-Riley Monte Carlo simulation method was used for reliability analysis of the considered system. The studied data was collected from an Iranian longwall coal mine for analysis. The MATLAB software was used for simulation and then reliability plot of water system in shearer machine was determined. The results show that the reliability of shearer machine reduces to almost zero in a period of 300h. Comparison between the results of analytical method and simulated reliability plot presents that for analyzed data set, in high reliability levels (28%≤), the simulation approach estimates the higher reliability than analytical method. The maximum difference between the results of analytical and simulation methods is 23%. However, in low reliability levels (≤28%) there is no remarkable difference between the methods.

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