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  • 51.
    Al-Douri, Yamur K.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Information assurance for maintenance of railway track2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Railway traffic is steadily increasing, having a negative impact on maintenance and resulting in decreased track availability, comfort, and safety. Swedish railway track maintenance mostly focuses on the actual track condition via a nationwide condition-based maintenance (CBM) strategy. For maintenance to be conducted in an appropriate way, data on the actual track condition must be accurate; furthermore, those data need to be converted into accurate information for maintenance decisions. An information assurance (IA) framework has the potential to deal with the system risks from a technical perspective. The framework is a guideline that can be implemented within CBM to understand both condition monitoring data behaviour and the information processing used to reach maintenance decisions.This research investigates ways of an information assurance (IA) framework can be implemented in the following CBM steps: data collecting, data processing and making maintenance decisions on Swedish railway. The framework can be used to understand data behaviour, information processing and the communication between information layers for decisions at organisation, infrastructure and data/information levels. The research uses both qualitative and quantitative methods to investigate critical information data, parameters, and problems and to suggest which areas need improvement. Quantitative analysis of the Swedish track geometry database reveals specific information about the behaviour of the railway data and their processing to make maintenance decisions.A case study shows how certain sections of a railway track are monitored and evaluates maintenance practices on those sections. The study finds several different types of measurements are taken using several different measurement systems. It is difficult to integrate these data for proper processing. In addition, there are problems of incomplete or irregular data; this affects the derivation of information and the use of models to understand track irregularities.Given the problems of data processing and subsequent decision making, the study suggests implementing an IA framework with CBM. The study checks the achievement of three IA principles in the existing data: authenticity, integrity and availability. The results show data have problems of authenticity and integrity, something also mentioned by the stakeholders in interviews. In particular years and on certain track sections, CM data are more than 5 percent incomplete, significantly affecting analysis. Incomplete track measurement data reach as high as 63 percent for the parameters of standard deviation (STD), longitudinal level and STD cooperation. Inaccurate measured values for alignment long wavelength within certain speed limits reach as high as 71 percent. These indicators are important for calculating track quality but are either incomplete or incorrect, negatively affecting the calculation of the Q-value and estimations of the track quality. This, in turn, negatively affects the maintenance decisions. Using information assurance will increase the system performance by permitting stakeholders to make accurate decisions.The suggested information assurance framework can discover technical problems but it needs to be improved using technologies, techniques and services to ensure complete and accurate data are available to be processed for maintenance decisions.

  • 52.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Al-Jumaili, Mustafa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Information security in e-maintenance: a study of Scada security2012Conference paper (Refereed)
    Abstract [en]

    eMaintenance solutions are spreading increasingly due to the continuous evolution in the different Information and Communication Technology (ICT) tools. In general, most of the available eMaintenance solutions are depending on Internet infrastructure what makes them vulnerable to all security threats that affect the Internet. One of the important eMaintenance solutions is Supervisory Control and Data Acquisition (SCADA) system as it has been used in most of the industrial processes. SCADA systems were designed without security considerations as they were mainly installed into isolated networks. Nowadays, SCADA systems are mainly connected to Internet and other networks. Therefore, SCADA systems have been exposed to wide range of network security threats. Hence, SCADA security has become an important aspect that needs to be investigated. In this paper, a study of SCADA security issues will be done. The main contribution of this paper is to address SCADA security issues and challenges related to eMaintenance.

  • 53.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Hamodi, Hussan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Data imputing using generic algorithms (GA)2017In: 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, p. 205-208Conference paper (Refereed)
  • 54.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Hamodi, Hussan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Lundberg, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Time Series Forecasting using a Two-level Multi-objective Genetic Algorithm: A case study of cost data for tunnel fans2018In: Algorithms, ISSN 1999-4893, Vol. 11, no 8, article id 123Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to develop a novel two-level multi-objective genetic algorithm (GA) to optimize time series forecasting data for fans used in road tunnels by the Swedish Transport Administration (Trafikverket). The first level is for the process of forecasting time series cost data, while the second level evaluates the forecasting. The first level implements either a multi-objective GA based on the ARIMA model or based on the dynamic regression model. The second level utilises a multi-objective GA based on different forecasting error rates to identify a proper forecasting. Our method is compared with the ARIMA model only. The results show the drawbacks of time series forecasting using the ARIMA model. In addition, the results of the two-level model show the drawbacks of forecasting using a multi-objective GA based on the dynamic regression model. A multi-objective GA based on the ARIMA model produces better forecasting results. In the second level, five forecasting accuracy functions help in selecting the best forecasting. Selecting a proper methodology for forecasting is based on the averages of the forecasted data, the historical data, the actual data and the polynomial trends. The forecasted data can be used for life cycle cost (LCC) analysis.

  • 55.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Hamodi, Hussan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Zhang, Liangwei
    Department of Industrial Engineering, School of Mechanical Engineering, Dongguan University of Technology, 523808 Dongguan, China.
    Data clustering and imputing using a two-level multi-objective genetic algorithms (GA): A case study of maintenance cost data for tunnel fans2018In: Cogent Engineering, ISSN 2331-1916, Vol. 5, no 1, p. 1-16, article id 1513304Article in journal (Refereed)
    Abstract [en]

    Data clustering captures natural structures in data consisting of a set of objects and groups similar data together. The derived clusters can be used for scale analysis and to posit missing data values in objects, as missing data have a negative effect on the computational validity of models. This study develops a new two-level multi-objective genetic algorithm (GA) to optimize clustering in order to redact and impute missing cost data for fans used in road tunnels by the Swedish Transport Administration (Trafikverket). The first level uses a multi-objective GA based on fuzzy c-means to cluster cost data objects based on three main indices. The first is cluster centre outliers; the second is the compactness and separation ( ) of the data points and cluster centres; the third is the intensity of data points belonging to the derived clusters. Our clustering model is validated using k-means clustering. The second level uses a multi-objective GA to impute the missing cost redacted data in size using a valid data period. The optimal population has a low , 0.1%, and a high intensity, 99%. It has three cluster centres, with the highest data reduction of 27%. These three cluster centres have a suitable geometry, so the cost data can be partitioned into relevant contents to be redacted for imputing. Our model show better clustering detection and evaluation compared with k-means. The amount of missing data for the two cost objects are: labour 57%, materials 81%. The second level shows highly correlated data (R-squared 0.99) after imputing the missing data objects. Therefore, multi-objective GA can cluster and impute data to derive complete data that can be used for better estimation of forecasting.

  • 56.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Parida, Aditya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Model-based security system for data acquisition in e-maintenance using artificial immune system and cloud computing2012In: International Journal of COMADEM, ISSN 1363-7681, Vol. 15, no 4, p. 26-37Article in journal (Refereed)
    Abstract [en]

    eMaintenance solutions are extensively used by the industry today. eMaintenance is an emerging technology aimed to support the industry to achieve effectiveness and efficiency in their maintenance process through enhanced use of Information and Communication Technology (ICT) . One of the essential components is an eMaintenance solution is data acquisition. Supervisory Control and Data Acquisition (SCADA) has been used to manage data acquisition is many industrial systems. Nowadays, modern SCADA systems are available through internet and other networks via IP protocol. An increased use of internet–based solution requires appropriate management approaches to improve the safety and security aspects of a system. Hence, this paper suggests a new security model based security for SCADA systems through Cloud computing and Artificial Immune System (AIS). Furthermore, the paper provides AIS, which is based on Decision Tree (C4.5 algorithm) using clustered feature set. The features set are selected from NSL-KDD cup. It is a new version of KDD dataset. As a result, two Antibodies are generated (that could recognize Normal and Antigen). After applying the resulted antibodies on the testing data set, the outputs are Normal, Antigen, and Unknown. Finally it is treated with Unknown as Antigen. As a result, high accuracy of the suggested model reaches 96.3%.

  • 57.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Pangracious, Vinod
    Department of Electrical and Computer Engineering, American University in Dubai,.
    Al-Doori, Mulhim
    Department of Electrical and Computer Engineering, American University in Dubai.
    Artifical Immune System Using Genetic Algorithm And Decision Tree2016In: International Conference on Bio-engineering for Smart Technologies (BioSMART) 2016, Piscataway, NJ: IEEE, 2016, p. 1-4, article id 7835603Conference paper (Refereed)
    Abstract [en]

    Artificial immune system (AIS) is considered as an adaptive computational intelligence method that could be used for detecting and preventing current computer network threats. AIS generates Antibodies (self) competent in recognizing Antigen (non-self), which is considered as an anomaly technique. This paper aims to develop artificial immune system (AIS) that consists of two levels. Level one is developed using Genetic Algorithm, while level two is developed using C4.5 decision tree algorithm. The proposed system trained with clustered features that are selected from NSL-KDD cup data-set. Each level produces two antibodies (that could recognize Normal and Antigen access-records). The recognition accuracy of the developed system reaches 96%. The behavior of each level is studied. The best feature-set that suits each level is specified.

  • 58.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    A critical review of Information Assurance (IA) framework forcondition-based maintenance of railway tracks2017In: Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016 / [ed] Walls L.,Revie M.,Bedford T, London: CRC Press, 2017, p. 1072-1078Conference paper (Refereed)
    Abstract [en]

    Railway maintenance is faced with increasing demands, including the need to improve service.Data measuring the track state and suitable models or applications are needed to make good maintenancedecisions. This critical review paper investigates many research papers on the use of information assurance (IA)within condition-based maintenance (CBM) on a railway track. An IA framework sheds light on the data andinformation used to make maintenance decisions. The paper considers work on data processing and decisionmakingin CBM. The results show condition monitoring suffers from an inability to determine exact positioningon the track; some data are inaccurate or unavailable. Existing studies have not adequately dealt with data contentor the various technologies used. They focus on integrity, availability, authentication, authorisation and accuracy,but do not consider other IA principles important to understand data.CBMmodels and algorithms have difficultyunderstanding degradation models, and data problems mean it is difficult to make good decisions. There is alack of long term maintenance plans. Models also need to be integrated for more realistic but not necessarilyoptimum solutions and to ensure practical predictions of maintenance. Some models focus on degradation, othersconsider prediction, and still others calculate the maintenance cost; it is difficult to combine these. Overall, dataare inaccurate, there is no testing phase using realistic data, and existing models are insufficient. This has anegative impact on maintenance decisions.

  • 59.
    Al-Douri, Yamur K.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Improvement of Railway Performance: A Study of Swedish Railway Infrastructure2016In: Journal of Modern Transportation, ISSN 2095-087X, E-ISSN 2196-0577, Vol. 24, no 1, p. 22-37, article id 2Article in journal (Refereed)
    Abstract [en]

    The volume of rail traffic was increased by 5% from 2006 to 2010, in Sweden, due to increased goods and passenger traffic. This increased traffic, in turn, has led to a more rapid degradation of the railway track, which has resulted in higher maintenance costs. In general, degradation affects comfort, safety, and track quality, as well as, reliability, availability, speed, and overall railway performance. This case study investigated the needs of railway stakeholders responsible for analysing the track state and what information is necessary to make good maintenance decisions. The goal is to improve the railway track performance by ensuring increased availability, reliability, and safety, along with a decreased maintenance cost. Interviews of eight experts were undertaken to learn of general areas in need of improvement, and a quantitative analysis of condition monitoring data was conducted to find more specific information. The results show that by implementing a long-term maintenance strategy and by conducting preventive maintenance actions maintenance costs would be reduced. In addition to that, problems with measured data, missing data, and incorrect location data resulted in increased and unnecessary maintenance tasks. The conclusions show that proactive solutions are needed to reach the desired goals of improved safety, improved availability and improved reliability. This also includes the development of a visualisation tool and a life cycle cost model for maintenance strategies.

  • 60.
    Aliyari, Mostafa
    et al.
    Politecnico di Milano.
    Barabadi, Abbas
    UiT The Arctic University of Norway.
    Barababadi, R.
    Amir Kabir College, Jajarm.
    Garmabaki, Amir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Failure and repair data analysis of power distribution systems: a case study2017In: Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016 / [ed] Walls L.,Revie M.,Bedford T, London: CRC Press, 2017, p. 2046-2053Conference paper (Refereed)
    Abstract [en]

    The basic function of electricity distribution system is to supply electrical energy as economically as possible to customer in different geographic with an accept-able level of reliability and quality [1]. The quality of electricity means the supplied current and voltage waveforms are essentially pure sinusoidal waveforms. By incorporating reliability and maintainability con-siderations in the system design and in the planning of system expansion, operation and maintenance the both quality and safety can be improved [2]. To obtain useful results from system reliability assessments, accurate values of component reliability parameters need to be estimated. If the outage database are collected properly, they can reflecting the conditions in which a component works. Hence, collecting, extraction and exploitation useful information from historical data getting more and more importance. A statistical significance of an outage database depends on the quality and reliability as well as number of records data in the database. Such database would describe the real conditions of network equipment more accurately. This study will exploit unplanned outages in electrical components of low voltage (LV) distribution systems in North Khorasan Electricity Distribution Company (NKEDC). The database containing 64035 outages and 150569 Kwh undistributed energy and total time of 2637430 minutes of outages in LV components from July 2010 to February 2016. Here, the main aim of the analysis is to identify the “Significant Few” failures as well as the current maintainability performance of each identified failure models in the power distribution. Such analysis will give a picture of current situation of the system. To start the analysis two meeting have been conducted with the expertise of company to identified the main failure model in the system. Thereafter, the collect data have been explored. The collected data are very detailed regarding the repair time. However, the recorded failure model and preliminary failure cause are not well collected in database. Moreover, we noticed that cause of the failure are not recorded using appropriate coding system that make extracting the data very difficult. Hence, at the first step appropriate coding system have been developed. In this stage, the required recommendation for improving the data collection have been provide and discussed with the company. Based on failure mechanism, of equipment and expert opinions 23 failure mode have been identified and then maintainability for these identified failure mode have been calculated. The trend test and the serial correlation test should all collected repair data are iid distributed and lognormal distribution is suitable tools to model the most identified failure modes

  • 61.
    Aljumaili, Mustafa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Data Quality Assessment: Applied in Maintenance2016Doctoral thesis, comprehensive summary (Other academic)
  • 62.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Data quality assessment using multi-attribute: maintenance perspective2018In: International Journal of Information and Decision Sciences, ISSN 1756-7017, E-ISSN 1756-7025, Vol. 10, no 2, p. 147-161Article in journal (Refereed)
    Abstract [en]

    The paper proposes a model for data quality (DQ) assessment in maintenance. Data has become an increasingly important since most of the maintenance planning and implementations are based on data analysis. Poor DQ reduces customer satisfaction, leading to poor decision making, and has negative impacts on strategy execution. To improve DQ as well as to evaluate the current status, DQ needs to be measured. A measure for DQ could be an important support for decision makers. Multi-criteria decision-making (MCDM) methods can provide a framework for DQ assessment, however, they are not used in literature for DQ assessment. In order to assess DQ, the attributes or KPIs need to be defined, their hierarchy should be designed and the assessment model is proposed to evaluate these attributes. A case study is also presented in this paper. The study shows that MCDM methods could provide qualitative estimation for the quality of DQ attributes.

  • 63.
    Aljumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Metadata-Based Data Quality Assessment2016In: Vine: The Journal of Information and Knowledge Management Systems, ISSN 0305-5728, E-ISSN 1474-1032, Vol. 46, no 2, p. 232-250Article in journal (Refereed)
    Abstract [en]

    High quality data and data quality assessment can support the decision-makingprocess. In the literature, discussions of the assessment process are mainly focused on theoretical approaches to content analysis or on user evaluations. Metadata is important source for quality information in any database system, however, it is not considered for data quality assessment. Metadata contains information that describes the data in a database, including the constraints and the database schema. High quality data can be produced by designing a database system with accurate metadata descriptions. Having accurate and detailed metadata will reduce the errors in data values which can lead to data quality issues. In this study, data quality assessment model is proposed based on both content and metadata analysis. The model is validated by developing an application tool to assess the quality of the data in a database based on the proposed model. The results show that metadata can provide important information about the quality of the database and its adoption can help togive faster, more accurate and user independent assessment of data quality.

  • 64.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Multi-Criteria Data Quality Assessment Maintenance perspective2014In: 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, p. 153-158Conference paper (Refereed)
    Abstract [en]

    Data quality (DQ) in maintenance has become an increasinglyimportant aspect to many firms as most of the maintenanceplanning and implementations are based on data analysis. PoorDQ has adverse effects at the operational, tactical, and strategiclevels of any organization. Respectively, poor DQ reducescustomer satisfaction, leading to poor decision making, and hasnegative impacts on strategy execution. To improve DQ as well asto evaluate the current status, DQ need to be measured followingthe fact that only what can be measured can be improved. Ameasure for DQ could be an important support for decisionmakers. In order to assess DQ, related attributes should bedefined. These attributes could be related to the data itself, to themetadata, or to the data representation schemes. After definingthese attributes, an assessment model should be used to evaluatethese attributes. The purpose of this paper is to propose a modelfor DQ assessment. Therefore, a study of DQ attributes and thepossible metrics that could be used to measure these attributes wasundertaken. The proposed model will be applied on datasetprovided by the Swedish Transport Administration (Trafikverket)for validation and to find an estimation measure of the DQ.

  • 65.
    Aljumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Quality of Streaming Data in Condition Monitoring Using ISO 80002016In: 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, p. 703-715Conference paper (Refereed)
    Abstract [en]

    The purpose of this paper is to propose a Data Quality Measurement Model based on ISO 8000 standard. This paper deals about the concepts implied in the measurement process, not about the measures themselves. Poor quality information causes customer dissatisfaction, lost revenue and higher costs associated with additional time to reconcile information. An understanding of the characteristics of the data that determine its quality, and an ability to measure, manage and report on data quality is required. Measurement is a major activity in data quality management. In literature, there are many proposals contributing somehow to the measurement of data quality. However, these measurement methods lack the unification. ISO 8000 provides a framework for improving data quality that can be used independently or in conjunction with quality management systems. ISO 8000 defines characteristics that can be tested by any organization in the data supply chain to objectively determine conformance of the data to ISO 8000.

  • 66.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Wandt, Karina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    eMaintenance Ontologies for Data Quality Support2015In: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 21, no 3, p. 358-374Article in journal (Refereed)
    Abstract [en]

    Purpose – The purpose of this paper is to explore the main ontologies related to eMaintenance solutions and to study their application area. The advantages of using these ontologies to improve and control data quality will be investigated.Design/methodology/approach – A literature study has been done to explore the eMaintenance ontologies in the different areas. These ontologies are mainly related to content structure and communication interface. Then, ontologies will be linked to each step of the data production process in maintenance.Findings – The findings suggest that eMaintenance ontologies can help to produce a high quality data in maintenance. The suggested maintenance data production process may help to control data quality. Using these ontologies in every step of the process may help to provide management tools to provide high quality data.Research limitations/implications – Based on this study, it can be concluded that further research could broaden the investigation to identify more eMaintenance ontologies. Moreover, studying these ontologies in more technical details may help to increase the understandability and the use of these standards. Practical implications – It has been concluded in this study that applying eMaintenance ontologies by companies needs additional cost and time. Also the lack or the ineffective use of eMaintenance tools in many enterprises is one of the limitations for using these ontologies.Originality/value – Investigating eMaintenance ontologies and connecting them to maintenance data production is important to control and manage the data quality in maintenance.Paper type Research Paper

  • 67.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Mahmood, Yasser Ahmed
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Assessment of railway frequency converter performance and data quality using the IEEE 762 Standard2014In: International Journal of Systems Assurance Engineering and Management, ISSN 0975-6809, E-ISSN 0976-4348, Vol. 5, no 1, p. 42694-Article in journal (Refereed)
    Abstract [en]

    Reliability, availability and maintainability analysis is one of the most important tools for measuring system performance. The performance of a traction power supply system (TPSS) can be measured using the data collected from frequency converters, as these converters constitute the main part of the TPSS. The quality of the collected data should be good enough to provide the correct and complete information necessary for assessment of frequency converter performance. Many methods can be used to assess the performance of converters such as neural networks, fuzzy logic and standards. The IEEE 762 Standard offers a methodology that can provide key performance indicators for power generation units. This standard has been chosen for its widespread acceptance and applicability. To be able to evaluate a converter’s performance, IEEE 762 indexes should be calculated using data such as the downtime, reserve shutdown hours and service hours. Therefore, the purpose of this study is to assess the performance of the Swedish TPSS frequency converters using IEEE 762, and to assess the quality of data by inspecting their compatibility with this standard. In this study, an application has been developed to generate the missing information and to calculate the indexes provided by the standard, in order to evaluate the power converters’ performance. A case with sample data is also discussed in this paper.

  • 68.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Rauhala, Ville
    Kemi-Tornio University of Applied Science.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Jonsson, Katrin
    Department of Informatics, Umeå University.
    Parida, Aditya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Aspects of data quality in eMaintenance: a case study of process industry in northern Europe2014In: Engineering Asset Management 2011: Proceedings of the Sixth World Congress on Engineering Asset Management / [ed] Jay Lee; Jun Ni; Jagnathan Sarangapani; Joseph Mathew, London: Encyclopedia of Global Archaeology/Springer Verlag, 2014, p. 41-51Conference paper (Refereed)
    Abstract [en]

    Increased environmental awareness in the industry combined with the globalized market economy makes increasing demands for sustainable and efficient resource utilization. In this context, maintenance plays a critical role by linking business objectives to the strategic and operational activities aimed at retaining the system’s availability performance, cost-efficiency and sustainability. Performing maintenance effectively and efficiently requires corresponding infrastructure for decision-support provided through eMaintenance solutions. A proper eMaintenance solution needs to provide services for data acquisition, data processing, data aggregation, data analysis, data visualization, context-sensing etc. To en Quality of Service (QoS) in eMaintenance solutions, the performance of both system-of-interest, enabling systems and related processes have to be measured and managed. However, the QoS has to be considered on all aggregation levels and encompass the aspects of Content Quality (CQ), Data Quality (DQ) and Information Quality (IQ). Hence, the purpose of this paper is to study and describe some aspects of DQ in eMaintenance related to process industry in northern Europe

  • 69.
    Aljumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Rauhala, Ville
    Kemi-Tornio University of Applied Science Technology.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Data quality in eMaintenance: a call for research2011In: MPMM 2011: Maintenance Performance Measurement & Management: Conference Proceedings / [ed] Diego Galar; Aditya Parida; Håkan Schunnesson; Uday Kumar, Luleå: Luleå tekniska universitet, 2011, p. 69-73Conference paper (Refereed)
    Abstract [en]

    Effective and efficient maintenance requires a proper information logistics, which can be delivered through eMaintenance solutions. Development of eMaintenance solutions faces extensive challenges. One of these challenges is how to ensure the quality of data used in different eMaintenance solutions. Data Quality (DQ) concerns all phases of the maintenance process. The purpose of this paper is to answer the research question: how should DQ be considered and managed when developing eMaintenance solutions. To deal with such challenges a case study was conducted at a mining company. Empirical data has been collected through interviews, observations, archival records and workshops. The data analysis has been based on an empirical framework that supports the identification of required information services. Conditions that support the DQ and the information logistics, along with that, support the maintenance process have been presented. These aspects have also been related to the phases of a generic maintenance process.

  • 70.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Tretten, Phillip
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Study of aspects of data quality in e-maintenance2012In: International Journal of COMADEM, ISSN 1363-7681, Vol. 15, no 4, p. 3-14Article in journal (Refereed)
  • 71.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Wandt, Karina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    eMaintenance ontologies and data production2012In: Proceedings of the 2nd International Workshop & Congress on eMaintenance: Dec 12-14 Luleå, Sweden : eMaintenace: trends in technologies and methodologies, challenges, possibilities and applications / [ed] Ramin Karim; Aditya Parida; Uday Kumar, Luleå: Luleå tekniska universitet, 2012, p. 191-196Conference paper (Refereed)
  • 72.
    Al-Jumaili, Mustafa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Wandt, Karina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    eMaintenance Related Ontologies2012Report (Other academic)
  • 73.
    Allahkarami, Zeynab
    et al.
    Faculty of Engineering, Department of Mining Engineering, University of Tarbiat.
    Sayadi, Ahmad Reza
    Tarbiat Modares University, Faculty of Engineering, Department of Mining Engineering, University of Tarbiat.
    Lanke, Amol
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Reliability Analysis of Motor System of Dump Truck for Maintenance Management2016In: 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, p. 681-688Conference paper (Refereed)
    Abstract [en]

    Dump truck is one of the main machinery in open pit mines. From an economic point of view, more than 50–60 % of production costs in open pit mines are allocated to hauling and loading costs, so it is important to keep equipment in good condition. Reliability is a useful tool for evaluating the performance of this machine. In this research, the reliability of motor subsystem of a dump truck in Miduk Copper Mine in Iran has been analyzed. The failure data were collected during 20 months of dump truck operation. Trend and serial correlation tests were used to validate the assumption of independent and identically distribution (IID). According to tests, the data are independent and identically distributed therefore the renewal process technique is used for modelling. For finding the best-fit distribution, different types of statistical distributions were tested using the Easyfit software. The analysis results indicated the time between failures (TBF) data obey the Weibull (3p) distribution. The developed model based on these data showed that the reliability of the motor subsystem decreases to a zero value after approximately 430 h of operation. Regarding to the obtained reliability plot, preventive reliability-based maintenance time interval for 90 % reliability levels for machine in the motor subsystem is 21 h.

  • 74.
    Alm, Ove
    Luleå tekniska universitet.
    Effects of water on the mechanical propreties and micro-strucures of granitic rock at high pressures and high temperatures1982In: Issues in rock mechanics: proceedings Twenty-Third Symposium on Rock Mechanics ; the University of California, Berkeley, California, August 25 - 27, 1982 / [ed] Richard E. Goodman, New York: Society of Mining Engineers of the American Institute of Mining, Metallurgical and Petroleum Engineers , 1982, p. 261-269Conference paper (Refereed)
  • 75.
    Alm, Ove
    Luleå tekniska universitet.
    Experimental deformation of granitic rocks1981In: Vol. 103, no 1, p. 134-136Article in journal (Refereed)
  • 76.
    Alm, Ove
    Luleå tekniska universitet.
    Experimental deformation of mylonitic rocks: results presented at the International Conference on the Effect of Deformation on Rocks, Göttingen, April 9-12, 19801980Report (Other academic)
  • 77.
    Alm, Ove
    Luleå tekniska universitet.
    Fine-grained granitic rocks experimentally deformed at high temperatures and high pressures1977Report (Other academic)
  • 78.
    Alm, Ove
    Luleå tekniska universitet.
    Influence of water on the strength and deformation properties of a granitic aplite at high pressures and temperatures1979Report (Other academic)
  • 79.
    Alm, Ove
    Luleå tekniska universitet.
    Mechanical testing of powders and powder compacts1983In: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 12, no 6, p. 302-311Article in journal (Refereed)
    Abstract [en]

    Results from standard triaxial, uniaxial and bending tests are presented. Triaxial tests were performed at pressures in the range 0-200 MPa. Both initial loose powder samples and cylindrical precompacted specimens were studied under hydrostatic conditions. Most of the total volume compaction occurred at pressures below 10 MPa. Triaxial tests with superimposed axial loads showed no softening despite a 30% shortening of the length of specimens which initially were 60 mm long. Specimens deformed in triaxial tests showed a higher density and a higher uniaxial compressive strength than specimens compacted under hydrostatic conditions

  • 80.
    Alm, Ove
    Luleå tekniska universitet.
    The effect of water on the mechanical properties and microstructures of granitic rocks at high pressures and high temperatures1982In: Issues in rock mechanics: twenty-third Symposium on Rock Mechanics, the University of California, Berkeley, California, August 25-27, 1982 / [ed] Richard E. Goodman; Francois E Heuze, Society of Mining Engineers of the American Institute of Mining, Metallurgical and Petroleum Engineers , 1982, p. 261-269Conference paper (Refereed)
  • 81.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Alm, B.
    Luleå tekniska universitet.
    Stephansson, Ove
    Luleå tekniska universitet.
    Experimental deformation of rocks from the Kiruna District, northern Sweden1988In: Proceedings of the seventh quadrennial IAGOD symposium: held in Luleå, Sweden, August 18-22, 1986 / [ed] Ebbe Zachrisson, Taylor and Francis Group , 1988, p. 75-82Conference paper (Refereed)
  • 82.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Bäckström, Gunnar
    Luleå tekniska universitet.
    Thermal conductivity of NaF at high pressures1979Report (Other academic)
  • 83.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Forslund, Josef
    Ljunggren, Christer
    Luleå tekniska universitet.
    Mattila, Ulf
    Luleå tekniska universitet.
    Mortensen, Tove-Heide
    Luleå tekniska universitet.
    Stephansson, Ove
    Luleå tekniska universitet.
    Bergmekaniska standardtester: en beskrivning av tester från Avdelningen för bergmekanik, Tekniska högskolan i Luleå1985Report (Other academic)
  • 84.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Jaktlund, Lise-Lotte
    Luleå tekniska universitet.
    Shaoquan, Kuo
    Academia Sinica.
    The influence of microcrack density on the elastic and fracture mechanical properties of Stripa granite1985In: Physics of the Earth and Planetary Interiors, ISSN 0031-9201, E-ISSN 1872-7395, Vol. 40, no 3, p. 161-179Article in journal (Refereed)
    Abstract [en]

    Presents results from a great number of mechanical tests on Stripa granite containing various amounts of microcracks. Variations in the microcrack density were obtained by shock-heating the rock at different temperatures in the range 100-600°C for 3 h. The results presented are obtained from sound velocity measurements, uniaxial compression tests, Brazilian tests and three-point bending tests. The density of microcracks in the heated rock is studied by means of optical microscopy, SEM and differential strain analysis

  • 85.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Norin, Jonas
    Luleå tekniska universitet.
    Olofsson, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Experimentella bestämningar av mekaniska egenskaper för hårdmetallpulver: slutrapport över pilotstudie1982Report (Other academic)
  • 86.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Olofsson, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Attempt to make accurate measurements of deformations of compressible soilds at high pressure and different states of stress1982In: High pressure in research and industry: 8th AIRAPT Conference, 19th EHPRG Conference, 17 - 22 August 1981, Institte of Physical Chemistry, University of Uppsala, Sweden ; proceedings / [ed] C.-M. Backman, Uppsala: Fysikalisk-kemiska inst., Univ , 1982, p. 619-622Conference paper (Refereed)
  • 87.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Röshoff, Kennert
    Luleå tekniska universitet.
    Andersson, Göran
    Identification of thermally induced microcracks in rock materials1983In: Proceedings: Appendix / International Conference on Subsurface Heat Storage in Theory and Practice, Stockholm, June 6-8, 1983, Stockholm: Statens råd för byggnadsforskning , 1983, p. 338-342Conference paper (Refereed)
  • 88.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Röshoff, Kennert
    Luleå tekniska universitet.
    Stephansson, Ove
    Luleå tekniska universitet.
    Microstructures and mechanical characteristics of the Tannas augen gneiss, Swedish Caledonides1980In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 102, no 4, p. 319-334Article in journal (Refereed)
    Abstract [en]

    The mechanical behaviour, microstructure and substructure of the classic Tannas augen gneiss of the Swedish Caledonides are presented. Progressive deformation of granodiorite to augen gneiss and mylonite is shown to take place in an isochemical environment with redistribution of megacrysts to surrounding matrix. Experimental deformation of natural rocks from the Tannas Augen Gneiss Nappe has been carried out in the temperature range of 20-600oC and under confining pressure of 100-700MPa. The highest strength found is for the fine-grained mylonite. The augen of the gneiss show brittle behaviour under all test conditions, and temperature has a limited effect on the ultimate strength of the matrix of the augen gneiss. Microstructures have been analysed by means of optical microscopy and transmission electron microscopy. The progressive deformation is brought about by dislocation glide and dislocation creep. Subgrain formation, recrystallization and straining of new grains are observed at all stages of the progressive deformation of the matrix while the augen behavior is brittle

  • 89.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Stephansson, Ove
    Luleå tekniska universitet.
    Experimental deformation of Augen-gneisses1979In: Mechanisms of deformation and fracture: proceedings of the interdisciplinary conference held at the University of Luleå, Luleå, Sweden, September 20-22, 1978 / [ed] Kenneth E. Easterling, Oxford: Pergamon Press, 1979, p. 173-186Conference paper (Refereed)
  • 90.
    Alm, Ove
    et al.
    Luleå tekniska universitet.
    Stephansson, Ove
    Luleå tekniska universitet.
    Experimental Deformation of Augen-gneisses1978Report (Other academic)
  • 91.
    Almgren, Gunnar
    Luleå tekniska universitet.
    Bergsingenjörsutbildningen i Luleå under omprövning1990In: Bergsmannen med Jernkontorets Annaler, ISSN 0284-0448, no 6, p. 18-20, 23Article in journal (Other academic)
  • 92.
    Almgren, Gunnar
    Luleå tekniska universitet.
    Education in mining and rock excavation in Sweden1984In: The 12th Congress of World Mining Congress, New Delhi, November 19-23, 1984, Calcutta: American Institute of Chemical Engineers, 1984Conference paper (Refereed)
    Abstract [en]

    Education in Mining and Rock Excavation in Sweden can be subdivided into higher education, upper secondary school education and in-service training. Higher education is provided at the University of Lulea and leads to a Masters degree and to a Licentiate or Doctor of Engineering degree in mining. The higher education curriculum was replanned in connection with the move to Lulea in 1972 from the Royal Institute of Technology in Stockholm to involve higher specialization and to cover both the mining and the underground construction sectors. The upper secondary school education is given at the College of Mining and Metallurgy in Filipstad and leads to a secondary-school engineering degree. In-service training courses are given for working professionals by the Division of Advanced Vocational Training in Lulea and by equipment suppliers. Vocational training is pursued at some upper secondary schools in cooperation with the mining companies.

  • 93.
    Almgren, Gunnar
    Luleå tekniska universitet.
    Large scale underground mining: proceedings of the International Symposium on Large Scale Underground Mining, Luleå 6-7 November 19851985Collection (editor) (Other academic)
  • 94.
    Almgren, Gunnar
    Luleå tekniska universitet.
    Luleå-högskolan och dess bergteknik1977In: JkA: Jernkontorets Annaler, ISSN 0280-4239, no 3, p. 58-60Article in journal (Other academic)
  • 95.
    Almgren, Gunnar
    Luleå tekniska universitet.
    Rock mechanics and the economics of cut and fill mining1981In: Application of rock mechanics to cut and fill mining: proceedings of the Conference on the application of rock mechanics to cut and fill mining, organized by the Departments of rock mechanics and soil mechanics, University of Luleå ... held at the University of Luleå, Sweden, from 1 to 3 June, 1980 / [ed] Ove Stephansson; Michael J. Jones, London: The Institution of Mining and Metallurgy , 1981, p. 28-35Conference paper (Refereed)
  • 96.
    Almgren, Gunnar
    et al.
    Luleå tekniska universitet.
    Almgren, T.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Just-in-time and right-in-space1996In: Minerals Industry International, ISSN 0955-2847, Vol. 1032, p. 26-29Article in journal (Refereed)
  • 97.
    Almgren, Gunnar
    et al.
    Luleå tekniska universitet.
    Berge, IvarNorwegian University of Science and Technology (NTNU), Trondheim.Matikainen, RaimoHelsinki University of Technology.
    Improvement of mine productivity and overall economy by modern technology1987Collection (editor) (Other academic)
    Abstract [en]

    The two volumes contain over 100 papers of which c40 are abstracted separately. The articles are organized into 6 sections (the first 2 in volume 1, the rest in 2): 1) effective use of geological and geomechanical information; 2) computers in mine planning and operations; 3) capital requirements, organization and productivity in mechanized mining; 4) developments in shaftsinking including alternative haulage systems; 5) mechanized scaling and rock support; 6) mining in arctic conditions (especially permafrost) including applications of artificial freezing.-M.A.Bass

  • 98.
    Almgren, Gunnar
    et al.
    Luleå tekniska universitet.
    Kumar, UdayLuleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.Vagenas, NickLuleå tekniska universitet.
    Mine mechanization and automation: proceedings of the second International Symposium on Mine Mechanization and Automation, Luleå, Sweden, 7-10 June 19931993Collection (editor) (Other academic)
  • 99.
    Almgren, Torgny
    Luleå tekniska universitet.
    An approach to long range production and development planning with application to the Kiruna Mine, Sweden1994Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The mining industry is increasingly oriented towards large scale mining and the planning concept of "Just in Time", which means activities starting and ending as late as possible without jeopardising production. The buffers, consisting of production blocks and development ahead of production, are then minimi. This, however, leads to a larger dependency on the quality of the output from the production systems. The Kiruna mine, Sweden, is a large scale mine and has a number of potential ore blocks with a content that varies in quality (Fe, P, K) and in quantity (ore tonnage). Ore production is restricted by operative and block sequencing constraints as well as by production requirements. A computerized planning model, based on operations research (multi period scheduling) has been developed to meet future demands on ore qualities and quantities. The model uses long range objectives, but can satisfy temporary short range demands without jeopardising the long range goals. A sub-optimal plan, made using the model, has been compared with a truly optimal plan. It is shown that, due to the unreliable information concerning the ore, the sub-optimal plan performs as well as the optimal one. The simulation process that was developed for this comparison is also used to estimate the need for production buffer blocks. Another buffer planning model is developed to determine when development work should take place in order to minimize the risk of additional costs, caused by an inability to start production on time. This algorithm considers the uncertainties in activity durations and is based on a Monte Carlo simulation using project networks and estimates the optimum development buffer.

  • 100.
    Almgren, Torgny
    Luleå tekniska universitet.
    Probabilistic time planning for underground mines1990In: International Journal of Mining and Geological Engineering, ISSN 0269-0136, Vol. 8, no 2, p. 91-109Article in journal (Refereed)
    Abstract [en]

    The advantages of probabilistic time planning techniques, compared to deterministic ones, are discussed and an approach to probabilistic planning is presented. The approach includes an analysis of disturbancy factors, and a method of estimating the distribution of project completion time by using Monte Carlo simulation. It is shown how this result may be used to calculate the need for development buffers, which also has been demonstrated on a particular case, the Oscar project, a sublevel stoping operation in the Kiruna mine, Sweden.

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