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  • 151.
    Björling, Sten-Erik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Integration of knowledge management systems and end-user interfaces for MPMM2011Ingår i: MPMM 2011: Maintenance Performance Measurement & Management: Conference Proceedings / [ed] Diego Galar; Aditya Parida; Håkan Schunnesson; Uday Kumar, Lulleå: Luleå tekniska universitet, 2011, s. 209-212Konferensbidrag (Refereegranskat)
    Abstract [en]

    Maintenance can be considered as a combined information and knowledge processing and management system. Effective knowledge, practices and experiences management is growing in importance, especially in advanced processes and management of advanced and expensive assets. Efforts of integrating maintenance knowledge management (MKM) processes with MKMM will be increasingly more important due to the increasing complexities of these overall systems – the context in which the performance measurements has been performed is also important input in the performance analysis. Integration of MKM in MPMM can result in higher quality of the decisions and actions in the maintenance processes and in the overall work to increase efficiency and decreasing costs in the organizations.Integration of MKM (Maintenance Knowledge Management – knowledge, experiences and practices management) with collaborative structures and interfacing abilities with qualified services for simulation, modeling and computations can be regarded as Intelligence-based Maintenance (iMaintenance).These infrastructures present in iMaintenance can further improve MPMM efforts due to possible utilization of more accurate property and context information and services – changes in installations, environmental factors etc. not easily integrated in current MPMM implementations.Integration of MPMM with iMaintenance solutions can also improve the interaction between management and the maintenance operators and also allow improved interaction and integration with production operators in the organization. MPMM can with this approach be integrated as a natural component in the overall ICT-based maintenance and collaboration solutions – the performance status reporting will be seen as a natural extension to the normal routines. In this context the usability of the end-user environments will be very important – especially when designing systems for mobile use by maintenance operators in the field.

  • 152.
    Björling, Sten-Erik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Modular tool concepts for sustainable product development environments2009Ingår i: Proceedings of the 2nd International Conference on Advanced Design and Manufacture / [ed] Daizhong Su; Quingbin Zhiang; Shifan Zhu, Trans Tech Publications Inc., 2009, s. 55-59Konferensbidrag (Refereegranskat)
    Abstract [en]

    An existing demonstrator for E-maintenance solutions for advanced aviation maintenance staff was extended to incorporate abilities as a collaborative environment for developers of sustain­able products. Most of the existing core concepts and functions in the demonstrator were found to be viable: work context management, modularisation, information and web services access. This paper pres­en­ts more in detail the modularization concept used in the demonstrator and its potential use in collaborative environments for sustainable prod­ucts developers. This concept if implemented allow faster integration of external web services and information sources into the sustainable product design work­flows and processes.

  • 153.
    Björling, Sten-Erik
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Baglee, David
    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.
    Singh, Sarbjeet
    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 knowledge management with fusion of CMMS and CM2013Ingår i: DMIN 2013 International Conference on Data Mining: 22nd -25th July 2013, Las Vegas, Nevada, USA, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Maintenance can be considered as an information, knowledge processing and management system. The management of knowledge resources in maintenance is a relatively new issue compared to Computerized Maintenance Management Systems (CMMS) and Condition Monitoring (CM) approaches and systems. Information Communication technologies (ICT) systems including CMMS, CM and enterprise administrative systems amongst others are effective in supplying data and in some cases information. In order to be effective the availability of high-quality knowledge, skills and expertise are needed for effective analysis and decision-making based on the supplied information and data. Information and data are not by themselves enough, knowledge, experience and skills are the key factors when maximizing the usability of the collected data and information. Thus, effective knowledge management (KM) is growing in importance, especially in advanced processes and management of advanced and expensive assets. Therefore efforts to successfully integrate maintenance knowledge management processes with accurate information from CMMSs and CM systems will be vital due to the increasing complexities of the overall systems.Low maintenance effectiveness costs money and resources since normal and stable production cannot be upheld and maintained over time, lowered maintenance effectiveness can have a substantial impact on the organizations ability to obtain stable flows of income and control costs in the overall process. Ineffective maintenance is often dependent on faulty decisions, mistakes due to lack of experience and lack of functional systems for effective information exchange [10]. Thus, access to knowledge, experience and skills resources in combination with functional collaboration structures can be regarded as vital components for a high maintenance effectiveness solution.Maintenance effectiveness depends in part on the quality, timeliness, accuracy and completeness of information related to machine degradation state, based on which decisions are made. Maintenance effectiveness, to a large extent, also depends on the quality of the knowledge of the managers and maintenance operators and the effectiveness of the internal & external collaborative environments. With emergence of intelligent sensors to measure and monitor the health state of the component and gradual implementation of ICT) in organizations, the conceptualization and implementation of E-Maintenance is turning into a reality. Unfortunately, even though knowledge management aspects are important in maintenance, the integration of KM aspects has still to find its place in E-Maintenance and in the overall information flows of larger-scale maintenance solutions. Nowadays, two main systems are implemented in most maintenance departments: Firstly, Computer Maintenance Management Systems (CMMS), the core of traditional maintenance record-keeping practices that often facilitate the usage of textual descriptions of faults and actions performed on an asset. Secondly, condition monitoring systems (CMS). Recently developed (CMS) are capable of directly monitoring asset components parameters; however, attempts to link observed CMMS events to CM sensor measurements have been limited in their approach and scalability. In this article we present one approach for addressing this challenge. We argue that understanding the requirements and constraints in conjunction - from maintenance, knowledge management and ICT perspectives - is necessary. We identify the issues that need be addressed for achieving successful integration of such disparate data types and processes (also integrating knowledge management into the “data types” and processes).

  • 154. Björling, Sten-Erik
    et al.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    ICT concepts for managing future challenges in e-maintenance2009Ingår i: 22nd International Congress on Condition Monitoring and Diagnostic Engineering Management: COMADEM 2009 ; June 9 - 11, 2009, San Sebastian, Spain, Miramar Palace / [ed] Aitor Arnaiz, Eibar: Fundaci n Tekniker , 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    The maintenance & operations fields are & will increasingly be dominated by information fragmentation, product & process complexities, increasingly important needs to access relevant knowledge in an ever faster pace, increased need for accurate analysis & implementation of the analysis results & need for more effective & accurate management.In addition to this the created solutions & processes also has to be effectively used in different work contexts including mobile work contexts & supporting interoperability with external ICT systems & processes. ICT-based frameworks should according to the factors & challenges described above be structured to be flexible enough to over time integrate new types of information & services, be usable both internally in the industrial facilities & in the field (mobile) & effectively act as a bridge between older & future ICT-systems. An example of such an integration approach is the PROTEUS project aiming at developing an "integrating" platform for maintenance management. The frameworks described during this presentation also will include modularised integration of not only data in existing maintenance systems and knowledge resources but also integration with web services (SOA), access & management of external computational services (analysis). These different modules will be accessible more dynamically than earlier web-based solutions. This in an environment that support several parallel work contexts & use not only in fixed networks but also in mobile / nomadic settings allowing a high degree of flexibility for the maintenance & operations staff.

  • 155.
    Björnström, Albert
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Flödeskalibrering: Analys av kalibreringsprocesser2018Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I december 2015 undertecknades Parisavtalet i syfte att skapa ett bättre globalt klimat. Enligt avtalet ska alla länders utsläpp redovisas till FN. En förutsättning för att Sverige ska kunna redovisa utsläppen är att nuvarande utsläppsnivåer är kända, varför mätning och beräkning av utsläpp är nödvändig.

     

    Det statligt ägda gruvbolaget Luossavaara Kiirunavaara AB (LKAB) driver järnmalmsgruvor i Malmfälten. Den järnmalmspellets som tillverkas vid kulsinterverket KK4 i Kiruna består till viss del av tillsatsmedel, som vid förbränning bildar koldioxid. Hur mycket tillsatsmedel som förbränns mäts med hjälp av två flödesmätare. För att säkerställa att dessa mätare har godkänd noggrannhet utförs årliga kalibreringar där uppmätt volym jämförs med en referensvolym. I syfte att säkerställa att LKAB:s kalibreringsmetod fungerar har ett externt företag utfört kalibrering med en annan metod där mätsensorer placeras på tillsatsmedelledningen. Resultaten mellan de två kalibreringsmetoderna skiljer sig avsevärt, vilket föranlett denna rapport.

     

    Syftet med arbetet är att ta fram förbättringsåtgärder för LKAB:s kalibreringsmetod samt presentera förslag på hur LKAB kan skapa bättre förutsättningar för den andra så kallade pulshastighetsmetoden. Genom att analysera respektive kalibreringsmetod och utföra mätningar, tester och beräkningar tas svagheter fram. Tester visar att en svaghet med LKAB:s kalibrering är att den nivåmätningsmetod som används är personberoende. Nivåmätning med laseravståndsmätare testas med gott resultat varför denna typ av mätning rekommenderas framöver.

     

    En svaghet med pulshastigheten är att den är känslig för variation av rörens innerdiameter. För att denna metod ska ge tillförlitliga resultat krävs ombyggnation av ledningar samt noga uppmätt innerdiameter.

     

    Noggrann flödesmätning leder till att nuvarande koldioxidutsläpp kan beräknas vilket skapar förutsättningar för fortsatt arbete mot uppställda miljömål. Flödesmätarna har även en betydande roll för produktkvaliteten i KK4 vilket innebär att denna rapport kan bidra till högre kvalitet och ekonomisk lönsamhet.

  • 156.
    Block, J.
    et al.
    Saab Aerotech, Linköping.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, T.
    Saab Aerotech, Linköping.
    Evaluation of preventive maintenance task intervals using field data from a complete life cycle2008Ingår i: IEEE Aerospace Conference Proceedings: -8 March 2008 : [Big Sky, Montana]., Piscataway, N.J: IEEE Communications Society, 2008, Vol. Article number 4526635, s. 1-11Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper the appropriateness of initial preventive maintenance task intervals and the improvement of changed intervals are evaluated. The evaluation criteria are partly derived from logic found in the RCM (Reliability-Centered Maintenance) methodology. Empirical data is related to the whole life cycle of the Swedish military aircraft system FPL 37 Viggen, from 1977 to 2006. The analysis shows that the maintenance intervals are partly appropriate and that some performed changes are improvements. These conclusions are strengthened if the phase-out of the aircraft system is considered, where the preventive maintenance strategy has been replaced with a corrective one, in order to achieve cost-effectiveness. Considering the perfect repair assumption, it seems that the overhaul tasks essentially bring the items back to a state as good as new. The performed evaluation mostly considers when the failures are recognized, i.e. during operation or during maintenance. Hence, aspects such as item accessibility, personnel skill levels, and maintenance task intervals for other items are not included in the evaluation.

  • 157.
    Block, J.
    et al.
    Logistic Analysis and Fleet Monitoring Division, Saab Aerotech.
    Tyrberg, T.
    Maintenance Information, Systems Division, Saab Aerotech.
    Fuqing, Yuan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Optimal repair for repairable components during phaseout an aircraft fleet2010Ingår i: IEEE Aerospace Conference Proceedings, Piscataway, NJ, 2010, artikel-id 5446880Konferensbidrag (Refereegranskat)
    Abstract [en]

    The successive removal of units from a group of systems during phasing out leads to a variable requirement for stock level of spare parts. Repairable units from phased out systems can be reused for the remaining functional systems in the group. Hence, the stock level of spare parts increases and the demand for spare parts decreases. This can lead to excessive stocking of spare parts and high maintenance costs for spare parts. This paper proposes a methodology to determine the optimum time to stop repair of repairable units to minimize the maintenance cost. It uses a Poisson Distribution based on NHPP (Non-Homogenous Poisson Process) to predict the available number of units, while fulfilling the demand for spare parts for the remaining systems. A concept, called Minimal Margin is introduced to formulate the problem and nonlinear programming is proposed to obtain the optimum solution. Finally, a numerical example is presented to demonstrate the approach

  • 158.
    Block, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Dependability analysis of military aircraft fleet performance in a lifecycle perspective2009Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Today's highly advanced technological flying platforms, such as aircraft, helicopters and Unmanned Air Vehicles (UAVs), are characterised by a high degree of complexity. Simultaneously, they are used in different operational and mission profiles, and also in multiple operational environments and geographical settings. In addition, the interaction between major stakeholders, such as operators and support providers, has been drastically changed by concepts such as Performance-Based Logistics (PBL), where the support providers' commitment increases through the offering of availability performance at a fixed price. These changes put new and stringent requirements on dependability analysis to make efficient use of field data (e.g. generated by built-in tests, operation and maintenance) to sustain, improve and predict the availability performance of flying platform fleets. The purpose of the research presented in this thesis is to explore and describe methodologies and tools for dependability analysis, modelling and simulation of fleets of complex systems, in order to support improvement decisions throughout the fleets' whole lifecycle. More specifically, the objective of the research is to contribute to the development of a tool for modelling and simulation of multiple parallel lifecycle phases of complex technical systems in a fleet. The focus is on the assessment of field data and the extraction and prediction of information for continuous improvement of subsystem reliability performance, organisational maintenance support performance and fleet availability performance. The empirical work focuses on the Swedish military aeronautics community. The data has been collected through interviews, observations, document studies and archival records, such as recordings of in-flight parameters and maintenance actions. The data has been analysed to investigate critical aspects, such as the perfect repair assumption, the appropriateness of decisions about changes of maintenance intervals and of the No Fault Found (NFF) phenomenon. Through a literature study and practical efforts, this thesis also outlines and exemplifies methodologies and tools that support dependability analysis of an aircraft fleet. In addition, modelling and simulation efforts have been made to enable prediction of aircraft fleet performance and beneficial adjustments of support resources during the fleet retirement phase. The results act as input to a conceptual model that describes the phasing-in, operation and retirement of an aircraft fleet. The model aims to identify when it is cost-effective to consider the Remaining Useful Life (RUL) of individual repairable components comprising aircraft being retired, and utilise these components as spare parts for the aircraft staying in service. In summary, the performed work indicates that, in today's context with PBL and excessive amount of available data, dependability analysis, modelling and simulation must become more transparent, traceable and intersubjective.

  • 159.
    Block, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. jan.block@saabgroup.com.
    Part-out Based Spares Provisioning and Management: A Study for Aircraft Retirement2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The operation and maintenance phase of a complex technical system may deal with strategicdecisions for asset retirement and end-of-life management. When a fleet of aircraft reachesthe retirement phase, the operation of remaining fleet should still be kept at a defined level ofavailability. Obviously, the provisioning of spares is a key issue to support the maintenanceand operation of the remaining fleet. The best practice within the aviation industry is to re-usethe spares of retired aircraft to support the operational fleet. This is referred to parting-out.The purpose of the research conducted for this thesis has been to develop decision supportmethodologies, models and tools for the management of a sustainable part-out-based sparesprovisioning for an aircraft fleet during its retirement period. The proposed methodology willbe used to support the retirement process of aircraft fleet and enhance the organisation’scapability of making efficient and cost-effective decisions concerning the re-use of spare partsduring the retirement period. To achieve the purpose of this research, literature studies, casestudies, algorithm development and simulations have been conducted. Empirical data havebeen collected through document studies, interviews, and the perusal of archival records fromSaab Support and Services AB. The data analysis performed for this research has been basedon theories and methodologies within reliability analysis, cost modelling, spares forecasting,stock provisioning and decision making, in combination with the best practices implementedby the aviation industry for the end-of-life management and retirement of aircraft.In the present thesis, part-out-based spares provisioning (PBSP) program is proposed to utiliseretired aircraft units effectively as spare parts. The proposed approach is illustrated andverified through a case study performed on the “Saab-105” military aircraft fleet withinSwedish air force fleet. A PBSP programme is proposed, associated management activitiesare described, the key decision criteria are presented, and a functional framework for aneffective PBSP is suggested. The proposed PBSP program provides a foundation for furthermeasures and tasks to be performed within the retirement period, such as terminatingmaintenance contracts, discarding internal maintenance capabilities, reviewing stocks, scalingdown administrative processes (e.g. spares procurement and obsolescence monitoring), etc.An important part of the PBSP programme is the reliability analysis of multiple repairableunits, and this has been investigated, using parametric and non-parametric reliabilityapproaches. The aim is to identify a practical approach for estimation of the future sparedemand at fleet level. Furthermore, a set of computational models and search algorithm havebeen developed for the identification of applicable termination times, of both the parting-outprocess and the maintenance and repair actions performed on the units. This includestermination of the parting-out process (PO), the sending of parted-out units directly to storage(POS), and repair actions performed on the units received at the repair shops owing tocorrective (CM) and preventive (PM) maintenance, as well as the parted-out units that need tobe repaired (POM). The feasible termination alternatives are compared with regard to theirrespective costs and the most cost-effective solutions are identified.The results of the research study show that a PBSP programme can yield large reductions inmaintenance and spares procurement costs, while supporting operation of existing fleet athighest required availability. It also contributes positively to implement a green supply chainduring the retirement phase. The methodology and approaches introduced within the thesiscan be applied in other civil applications, such as energy, mining, process industry andtransportation sectors.

  • 160.
    Block, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, Tommy
    Saab Support and Services.
    Using Monte Carlo simulation as support for decision making while negotiating a PBL contract2014Ingår i: IEEE Aerospace Conference. Proceedings, ISSN 1095-323X, artikel-id 6836495Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In connection with performance-based logistics (PBL) contracts for aircraft fleets it is very important to carefully analyse both operations and maintenance before and during the contract negotiation phase. Monte Carlo Simulation is a valuable methodology in this context since it allows delimiting and exploring a complex parameter space in a transparent and relatively easily visualized manner. With timely analyses it is possible to identify both technical and economic risks and minimize the possible consequences, a process that benefits both parties in the negotiation process. This paper describes a part of this process in connection with the negotiation of a PBL contract for the Swedish Air Force SAAB 105 (SK 60) trainer fleet between Saab AB and the Swedish Defence Materiel Administration (FMV). The information used in the simulations was largely empirical data derived from previous operations of the aircraft system. The main factors that were simulated were operational requirements, fleet size, spares inventories, turn-around times, failure rates and influence of extraneous factors (e. g. weather). The simulations resulted in considerable savings due to reduction of the active fleet size, and increased reclamation of surplus spares and units from retired aircraft.

  • 161.
    Block, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, Tommy
    Saab Support and Services.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Fleet-level reliability analysis of repairable units: a non-parametric approach using the mean cumulative function2013Ingår i: International Journal of Pedagogy, Innovation and New Technologies, ISSN 0973-1318, E-ISSN 2392-0092, Vol. 9, nr 3, s. 333-344Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Complex technical systems are normally repaired rather than replaced when they fail. It is often desirable to analyze the reliability characteristics of these systems based on data generated in a customer use environment, in order to assess the reliability, frequency of failure or other parameters which may be influenced by the systems’ age and usage. Despite the advantages of continuously analyzing reliability data to be able to improve the maintenance programme continuously, methods such as parametric and non-parametric analysis are often ignored due to a belief that the mean time between failures (MTBF) is sufficient to describe the reliability pattern of repairable units. This paper describes the use of the mean cumulative function (MCF) and linear estimates based on the recurrence rate to predict the expected number of failures in the future. Reliability data from two repairable units are used to verify the procedure and comparison. The empirical data used in the paper is based on field data gathered during the operational life of the Swedish military aircraft system FPL 37 Viggen from 1977 to 2006, which essentially is the whole life cycle of the system.

  • 162.
    Block, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, Tommy
    Saab Aerotech.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Fleet-level Reliability of Multiple Repairable Units: a Parametric Approach using the Power Law Process2014Ingår i: International Journal of Pedagogy, Innovation and New Technologies, ISSN 0973-1318, E-ISSN 2392-0092, Vol. 10, nr 3, s. 239-250Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The application of parametric reliability analysis methods for repairable units, such as Power law process, is quite clear and straightforward for a single repairable unit. However, in practice, the analyst needs to know the reliability characteristics of units at a fleet level. The application of parametric reliability analysis methods at the fleet level, even if it is limited in scope, is quite complex. The aim of this paper is to describe the use of the power law process for multiple repairable units with differing reliability characteristics, to predict the expected number of failures at fleet level. The empirical data used in the paper are based on field data gathered during the operational life of two types of multi repairable units used in the Swedish military aircraft system FPL 37 Viggen from 1977 to 2006. The paper performs the trend test using TTT-based MIL-HDBK-189 and Laplace tests, and assesses the equality of shape-parameters for the intensity function of the power law process for multiple units. Estimation of the scale- and shape-parameters using maximum likelihood estimation is also performed. The parametric approach using power law process was found to yield relatively accurate estimations of number of failures, compared to empirical data

  • 163.
    Block, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, Tommy
    Logistics Analysis and Fleet Monitoring, Saab Support and Services, Linköping.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Part-out-based spares provisioning management: A military aviation maintenance case study2014Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 20, nr 1, s. 76-95Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose – The purpose of this paper is to present the prerequisites for a part-out-based spares provisioning (PBSP) programme during the phase-out of an aircraft fleet. Furthermore, associated key decision criteria are identified and a framework for the phase-out management process is presented. Design/methodology/approach – Once a decision has been taken to phase-out an aircraft fleet, a number of routines for operations, maintenance and storage are affected and new tasks and functions must be introduced before initiating the actual parting-out process. A decision-making system and a management framework is needed to manage spares planning during the end-of-life phase to ensure availability at minimum cost and to ensure a manageable risk of backorders. Findings – For PBSP programme during the phase-out of an aircraft fleet to succeed and be cost-effective, a number of linked processes, tasks and decisions are required, e.g., those included in the framework proposed in this paper (see Figure 3). A successful implementation of PBSP also requires that these processes and tasks are carried out in a timely manner and that the communications between the concerned parties are prompt, clear and direct. One experience from the studied case is that close and trustful contacts and cooperation between the operator and maintenance provider(s) will greatly facilitate the process. Originality/value – Although the PBSP method is fairly commonly applied within both the military and the civilian sector, somewhat surprisingly very literature has been published on the subject. Indeed, remarkably little has been published on any aspects of maintenance during the end-of-life period.

  • 164.
    Block, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. Saab Support and Services, Logistics Analysis and Fleet Monitoring, Lifecycle Logistics Division, Linköping, Sweden.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Xun, Xiao
    School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Spares Provisioning Strategy for Periodically Replaced Units within the Fleet Retirement Period2019Ingår i: International Journal of Systems Assurance Engineering and Management, ISSN 0975-6809, E-ISSN 0976-4348, Vol. 10, nr 3, s. 299-315Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Within aviation enterprises, the process of dismantling an aircraft at the end of its life is referred to as parting-out. Obviously, the asset value of the units and materials parted out from the retired airframes can be considerable. The benchmarked best practice within the aviation industry is to dismantle the retired aircraft and use the parted-out spares to support the remaining fleet or to offer them on the surplus market. Part-out-based spares provisioning (PBSP) has been a major focus of attention for aviation companies. The PBSP approach is a complex task that requires a multidisciplinary and integrated decision-making process. In order to control the stock level and fulfil the decision criteria within PBSP, it is necessary to make decisions on the termination, at specific times, of both the parting-out process and the maintenance and repair actions performed on the units.

    This paper considers repairable units and introduces a computational model to identify the applicable alternatives for repair termination times that will minimize the number of remaining spares at the end of the retirement period, while fulfilling the availability requirement for spares during the PBSP period, at the lowest possible cost.  The feasible alternatives are compared with regard to their respective costs, and the most cost-effective solution is selected. The cost model uses estimates of future maintenance requirements, the turn-around times, the cost of the various maintenance tasks, the future spares consumption, and the estimated salvage of spares from retired aircraft. The output of the model is a set of applicable alternatives which satisfy the availability requirements for spares for the active fleet. The method is illustrated using a case study performed on the Saab-105 training aircraft. 

    The results show that the proposed PBSP approach and computational model provide added value from a sustainability point of view, since the use of existing resources is maximized during the retirement process, through the process of reclaiming units and the applicable maintenance termination alternatives. The implementation of the proposed computational model in a PBSP programme provides a detailed and situation-based overview of the stock level dynamics, and contributes to the spares provisioning process by providing solutions to issues such as obsolescence, last-time buys and cannibalization.

  • 165. Block, Jan
    et al.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, Tommy
    Saab Aerotech.
    Changes in items' failure pattern during maintenance: an investigation of the perfect repair assumption2008Ingår i: Annual Reliability and Maintainability Symposium, 2008: RAMS 2008 ; Las Vegas, Nevada, USA, 2008, 28 - 31 Jan, Piscataway, NJ: IEEE Communications Society, 2008, s. 117-122Konferensbidrag (Refereegranskat)
    Abstract [en]

    It is clear that the simple ‘perfect repair' assumption is not immediately applicable to any of the studied types of hardware, i.e. Cooling Turbine, High-Voltage Generator, Hydraulic Accumulator, and Radar Transmitter. Hence, the assumption of ‘perfect repair' needs to be validated for each specific type of item. Assumptions based on the type of physical hardware (e.g. mechanical item or avionics item) are not always trustworthy.Strangely enough the ‘perfect repair' assumption fits best for the Cooling Turbine, which is a highly stressed mechanical item, while the fit is much poorer for the Radar Transmitter, which is an avionics item and for the Hydraulic Accumulator.For the Radar Transmitter the trend seems to be very scattered. For items with a large number of failures early in their life-cycle, repair is ‘better than perfect', i.e. the items become more reliable after repair, presumably by elimination of less reliable subcomponents. However, this effect is not seen for items with few failures early in their life-cycle. For these items ‘perfect repair' initially seems to be a valid model. However, in many cases repair becomes ‘less than perfect' later in the life-cycle. For the Hydraulic Accumulator this trend is even more accentuated and individual items seem to fall into two distinct subpopulations with opposite reliability trends.

  • 166.
    Block, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tyrberg, T.
    Saab Aerotech.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    No Fault Found events during the operational life of military aircraft items2009Ingår i: 8th International Conference on Reliability, Maintainability and Safety, 2009: ICRMS 2009 ; 20 - 24 July 2009, Chengdu, China / [ed] Rui Kang, Piscataway, NJ: IEEE Communications Society, 2009, s. 920-924Konferensbidrag (Refereegranskat)
    Abstract [en]

    No fault found (NFF) events are critical and well-known problems for certain aircraft items. This paper presents a study of these events for repairable items with on-condition maintenance, based on operational data from a military aircraft. Some findings are that: the number of NFF events is influenced by item type and number of repairs; most NFF events are initiated by faults recognized during operation; and different inspections contribute to NFF events. Hence, item design and tests at different operational modes and maintenance echelons should be better aligned to reduce the number of NFF events

  • 167.
    Bo, Lin
    et al.
    The State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing, China.
    Xu, Guanji
    The State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing, China.
    Liu, Xiaofeng
    The State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing, China.
    Lin, Jing
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Bearing Fault Diagnosis Based on Subband Time-Frequency Texture Tensor2019Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 37611-37619Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The texture feature tensor established from a subband time–frequency image (TFI) was extracted and used to identify the fault states of a rolling bearing. The TFI of adaptive optimal-kernel distribution was optimally partitioned into TFI blocks based on the minimum frequency band entropy. The texture features were extracted from the co-occurrence matrix of each TFI block. Based on the order of the segmented frequency bands, the texture feature tensor was constructed using the multidimensional feature vectors from all the blocks; this preserved the inherent characteristic of the TFI structure and avoided the information loss caused by vectorizing multidimensional features. The linear support higher order tensor machine based on the feature tensor was applied to identify the fault states of the rolling bearing.

  • 168.
    Bonnet, Benjamin
    et al.
    Alstom Transport Information Solution.
    Parahy, Marine
    Luleå University of Technology.
    Dersin, Pierre
    Alstom Transport Information Solution.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Optimization of maintenance policy based on operational reliability analysis: application to railway switches & crossings2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The present communication reports on a collaboration between ALSTOM Transport and Luleå Technology University, under the sponsorship of Trafikverket, the Swedish Infrastructure Manager.For 2020, the European Rail Research Advisory Council (ERRAC) has set among other the following objectives [2] : doubling passenger traffic and tripling freight traffic and reducing the life-cycle cost of infrastructure by 30%.This need applies to rail infrastructure in general. Clearly, the highest leverage will be obtained by concentrating the efforts on key cost and availability drivers. For instance, it is reported that switches and crossings (S&C) are one of the subsystems that cause the most delays on Swedish Railways while accounting for at least 13% of maintenance costs. (It is the main reason why we chose to base our study on this subsystem).Intelligent data processing allows to understand the real reliability characteristics of the assets to be maintained. Furthermore simulation and optimisation techniques are applied in order to adapt the maintenance strategy so as to achieve minimum cost while guaranteeing target availability.The first step has been to determine the S&C reliability characteristics based on field data collection. Because field failure data are typically strongly censored, we have developed our own statistics software package to process field failure data, as commercial packages have not been found satisfactory in that respect. The resulting software, named RDAT® (Reliability Data Analysis Tool) has been relied upon for this study: it is especially adapted to statistical failure data analysis. The next step will be to customize the maintenance interval by adapting it to individual switches and crossings behaviour characteristics. In order to predict and optimize life-cycle cost (LCC) and availability, Monte Carlo simulations will be performed with stochastic Petri nets. The failure rates estimated with RDAT® will be used as inputs to the Petri net. Such a model lends itself to maintenance optimization. Indeed, designs of experiments can be used in conjunction with simulations in order to express both LCC and availability as functions of various maintenance-related decision variables (such as preventive maintenance frequency, maintenance efficiency, etc, see [7]).Further improvement could result from applying condition-based maintenance, where preventive maintenance times would no longer be predetermined but rather based on the observed S&C condition, as measured by : number of displacement cycles, current absorbed, vibration intensity during train passage, traffic intensity etc. It is planned to resort to the Watchdog Agent ® software, of Intelligent Maintenance System, to that end [4].

  • 169.
    Burström, Lage
    et al.
    Luleå tekniska universitet.
    Nilsson, Christer
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Manöverrum i stålindustrin: Delrapport 4 : Krav och riktlinjer1981Rapport (Övrigt vetenskapligt)
  • 170.
    Burström, Lage
    et al.
    Luleå tekniska universitet.
    Ågren, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Nilsson, Christer
    Luleå tekniska universitet.
    Manöverrum i stålindustrin: Delrapport 6, Referensrum SSAB Luleå, Slutrapport1981Rapport (Övrigt vetenskapligt)
  • 171.
    Cai, Baoping
    et al.
    College of Mechanical and Electronic Engineering, China University of Petroleum, Qingdao.
    Huang, Lei
    College of Mechanical and Electronic Engineering, China University of Petroleum, Qingdao.
    Lin, Janet
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Xie, Min
    Department of Systems Engineering and Engineering Management, City University of Hong Kong, Kowloon.
    Bayesian Networks in Fault Diagnosis: some research issues andchallenges2017Ingår 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. 26-32Konferensbidrag (Refereegranskat)
  • 172.
    Cai, Baoping
    et al.
    China University of Petroleum, Qingdao, Shandong, China.
    Kong, Xiangdi
    China University of Petroleum, Qingdao, Shandong, China.
    Liu, Yonghong
    China University of Petroleum, Qingdao, Shandong, China.
    Lin, Jing
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. China University of Petroleum, Qingdao, Shandong, China.
    Yuan, Xiaobing
    China University of Petroleum, Qingdao, Shandong, China.
    Xu, Hongqi
    Rongsheng Machinery Manufacture Ltd. of Huabei Oilfield, Hebei, Renqiu, China.
    Ji, Renjie
    China University of Petroleum, Qingdao, Shandong, China.
    Application of Bayesian Networks in Reliability Evaluation2019Ingår i: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 15, nr 4, s. 2146-2157Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Bayesian network (BN) is a powerful model for probabilistic knowledge representation and inference and is increasingly used in the field of reliability evaluation. This paper presents a bibliographic review of BNs that have been proposed for reliability evaluation in the last decades. Studies are classified from the perspective of the objects of reliability evaluation, i.e., hardware, structures, software, and humans. For each classification, the construction and validation of a BN-based reliability model are emphasized. The general procedural steps for BN-based reliability evaluation, including BN structure modeling, BN parameter modeling, BN inference, and model verification and validation, are investigated. Current gaps and challenges in reliability evaluation with BNs are explored, and a few upcoming research directions that are of interest to reliability researchers are identified.

  • 173.
    Calle Cordón, Álvaro
    et al.
    CEMOSA, Spain.
    Jiménez-Redondo, Noemi
    CEMOSA, Spain.
    Morales-Gámiz, J.
    CEMOSA, Spain.
    García-Villena, F. A.
    CEMOSA, Spain.
    Peralta-Escalante, J.
    CEMOSA, Spain.
    Garmabaki, Amir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Famurewa, Stephen Mayowa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Duarte, Emanuel
    Infraestruturas de Portugal, Lisbon, Portugal.
    Morgado, João
    Infraestruturas de Portugal, Lisbon, Portugal.
    Combined RAMS and LCC analysis in railway and road transport infrastructures2018Ingår i: Proceedings of 7th Transport Research Arena TRA, Vienna, Austria, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Life-cycle cost (LCC) analysis is an assessment technique used to evaluate costs incurred during the life-cycle of a system to help in long term decision making. In railway and road transport infrastructures, costs are subject to numerous uncertainties associated to the operation and maintenance phase. By integrating in the LCC the stochastic nature of failure using Reliability, Maintainability, Availability and Safety (RAMS) analyses, maintenance costs can be more reliably estimated. This paper presents an innovative approach for a combined RAMS&LCC methodology for linear transport infrastructures which has been developed under the H2020 project INFRALERT. Results of the application of such methodology in two real use cases are shown, one for rail and another one for road. The use cases show how the approach is implemented in practice.

  • 174.
    Calle-Cordón, Álvaro
    et al.
    CEMOSA.
    Jiménez-Redondo, Noemi
    CEMOSA.
    Morales-Gámiz, F. J.
    CEMOSA.
    García-Villena, F.A.
    CEMOSA.
    Garmabaki, Amir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Odelius, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Integration of RAMS in LCC analysis for linear transportinfrastructures: A case study for railways2017Ingår i: IOP Conference Series: Materials Science and Engineering, ISSN 1757-8981, E-ISSN 1757-899X, Vol. 236Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Life-cycle cost (LCC) analysis is an economic technique used to assess the totalcosts associated with the lifetime of a system in order to support decision making in long termstrategic planning. For complex systems, such as railway and road infrastructures, the cost ofmaintenance plays an important role in the LCC analysis. Costs associated with maintenanceinterventions can be more reliably estimated by integrating the probabilistic nature of thefailures associated to these interventions in the LCC models. Reliability, Maintainability,Availability and Safety (RAMS) parameters describe the maintenance needs of an asset in aquantitative way by using probabilistic information extracted from registered maintenanceactivities. Therefore, the integration of RAMS in the LCC analysis allows obtaining reliablepredictions of system maintenance costs and the dependencies of these costs with specific costdrivers through sensitivity analyses. This paper presents an innovative approach for acombined RAMS & LCC methodology for railway and road transport infrastructures beingdeveloped under the on-going H2020 project INFRALERT. Such RAMS & LCC analysisprovides relevant probabilistic information to be used for condition and risk-based planning ofmaintenance activities as well as for decision support in long term strategic investmentplanning.

  • 175.
    Candell, Olov
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Development of information support solutions for complex technical systems using eMaintenance2009Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Spridningen och användningen av komplexa tekniska system är vanliga i samhället och inom industrin. Många av de komplexa tekniska systemen har stränga krav på säkerhet, tillförlitlighet och kostnader, vilket kräver frekventa uppdateringar och ändringar till följd av ny teknisk utveckling och förändrade funktionskrav. Därför är korrekt, kontextanpassad och aktuell information och informationsstöd avgörande för åtkomst, förvaltning, underhåll och förbättring av de kravställda tjänster som skall tillhandahållas av dessa system. Med tanke på den tekniska utvecklingen och föränderliga företagsklimat, behöver system- och supportleverantörer förbättra utformning och tillhandahållande av lösningar för informationssupport. Detta kan underlättas genom användning av ny och innovativ informations- och kommunikationsteknologi, (IKT) vilka visar sig i form av nya metoder såsom eMaintenance. Det finns dock fortfarande ett behov av metoder och verktyg för utveckling och tillhandahållande av informationssupport genom en integration av affärs- och underhållsprocesser hos både kunder och leverantörer, för att åstadkomma nya affärslösningar såsom Prestandabaserad Logistik (PBL) i de sammanhang som beskrivs ovan. Syftet med denna forskning är därför för att beskriva hur leverantörer av supportlösningar kan utveckla och erbjuda effektiv informationssupport som stöd kopplat till komplicerade tekniska system genom ökad användning av IKT. För att uppnå detta syfte, har en fallstudie inom militär luftfarten utförts. Empiriska data har samlats in genom intervjuer, observationer, arkivstudier, workshops och deltagande forskning. Analysen baseras på befintlig, anpassad och utvecklade teorier, modellbaserade simulering och tillgängliga internationella standarder, i beaktande av ett ramverk för eMaintenance. Resultaten av forskningen är: I) en definition av service-, process- och livscykelorientede eMaintenance lösningar, II) en identifiering av kunders och leverantörers kritiska krav på information och informationssupport III) en identifiering av IKT-relaterade metoder och teknologier lämpade att uppfylla kunder och leverantörers krav på informationssupport, IV) ett tillvägagångssätt för utveckling och tillhandahållande av IKT-baserade lösningar för informationssupport som uppfyller kraven från kunder och leverantörer. Även om dessa resultat erhållits inom kontexten för ett modernt militärflygplan, indikerar resultat erhållna i forskningsprocessen att de i stor utsträckning är allmänna till sin karaktär och kan vara tillämpliga på andra komplexa tekniska system inom processindustrin, elproduktion och transportindustri.

  • 176.
    Candell, Olov
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Development of user information products for complex technical systems2004Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Interaktion med tekniska system är en del av det dagliga livet. System byggda av människan har uppnått aldrig tidigare skådade nivåer av komplexitet, vilket ställer nya krav på de organisationer som utvecklar och tillverkar dem. Samtidigt används de ofta i miljöer, som ställer mycket höga krav på säkerhet, trovärdighet och tillförlitlighet. Som användare av komplexa system behöver människan stöd för att kunna utnyttja och upprätthålla den nytta och de tjänster systemet i fokus levererar. Vid sidan av mera traditionellt stöd som service och underhåll, innefattar kundstöd även omfattande dokumentation. Trots en enorm utveckling av system för hantering av dokumentation avseende komplexa produkter är det fortfarande ett problem för användare att få tillgång till information och att förstå den. Utvecklingsmetoder för användarinformation behöver därför utvecklas och förbättras. Syftet med den aktuella studien är att utforska och beskriva utvecklingen av inressentbaserade informationsprodukter för komplexa tekniska system. Den kunskap som söks är en modell som kopplar ihop teori med praktisk tillämpning, d.v.s. arbetssätt och verktyg som kan stödja utveckling och ständiga förbättringar av intressentbaserade informationsprodukter för komplexa tekniska system. För att uppfylla syftet har en fallstudie, stödd av en litteraturstudie, genomförts. Fallstudien fokuserar på ett modernt stridsflygplan, som är ett ytterst komplext system med stränga krav på användarinformation. En utvecklingsmetod för användarinformationsprodukter har anpassats och sedan tillämpats och studerats under utvecklingen av en demonstrator. Studiens resultat kan beskrivas i två delar. Den första delen är en identifiering av arbetssätt och verktyg för kravinsamling och utveckling av användarinformationsprodukter. Dessa har identifierats inom områdena kognitionsvetenskap, människa-maskin-system, kvalitetsteknik och kravhantering. Den andra delen är resultatet av ett prov av det föreslagna arbetssättet genom utveckling av en demonstrator. Jämfört med ett traditionellt utvecklingssätt bidrar det föreslagna arbetssättet till ett ökat intressentfokus och en mer effektiv kommunikation mellan utvecklare och intressenter och även inom det tvärfunktionella teamet av utvecklare. Arbetssättet underlättar och förbättrar även kravhanteringen samt bidrar till att minska affärsrisker kopplade till feltolkningar och meningsskiljaktigheter kring en produktspecification.

  • 177.
    Candell, Olov
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Karim, Ramin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    eMaintenance: information driven maintenance and support2008Ingår i: Proceedings of the 18th International Conference on Flexible Automation and Intelligent Manufacturing: June 30th - July 2nd, 2008, Skövde, Sweden / [ed] Leo J. de Vin, Skövde: Högskolan i Skövde , 2008, s. 365-372Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today's providers of maintenance and in-service support related to modern aircraft are facing major challenges. A central problem with maintenance and support of aircraft and other complex technical systems is to manage the ever-increasing information flow and system complexity. Both military and commercial operators need to reduce downtime and one way to do this is to speed up the turnaround time for scheduled and unscheduled maintenance, or even better, to reduce the need thereof by implementing condition based maintenance. In order to implement these improved support solutions in a global support environment, eMaintenance is seen as one important building block. eMaintenance includes monitoring, collection, recording and distribution of real-time system health data, maintenance generated data as well as other decision and performance support to all stakeholders independent of organization or geographical location, 24 hours a day, 7 days a week (24/7). eMaintenance has the potential to improve the management and performance of activities related to the maintenance process, and thereby improve the dependability, safety and life cycle cost of critical systems. This is realized through the application of Information & Communication Technology (ICT) throughout the maintenance and support processes, thus integrating built-in tests, external tests at different maintenance echelons, technical information, diagnostics, prognostics and other sources of support information. The purpose of this paper is to present some results from a joint academic and aerospace industry research project, describing requirements and expectations that are important in a global support environment, and also to propose some central components in an eMaintenance framework that integrates maintenance and ICT perspectives.

  • 178.
    Candell, Olov
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Karim, Ramin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Parida, Aditya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Development of information system for e-maintenance solutions within the aerospace industry2011Ingår i: International Journal of Pedagogy, Innovation and New Technologies, ISSN 0973-1318, E-ISSN 2392-0092, Vol. 7, nr 6, s. 583-592Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Maintenance and support providers to modern aircraft need to manage an increasing amount of information generated by growing system complexity and stakeholder requirements. This introduces new risks in the information management process and makes traditional information services and systems inadequate. However, recent advancements in information and communication technology (ICT) have contributed to the emerging approach of e-Maintenance, which forms an important building block to achieve the desired information logistics. e-Maintenance enables remote and real time maintenance, and includes; collection, monitoring, analysis and distribution of data and information as decision-support to stakeholders of the maintenance and support processes, independent of organization or geographical location, 24 hours a day and 7 days a week (24/7). This paper describes a proposed development of information products by linking theories to practical methodologies and tools (e.g., Quality Function Deployment, QFD) through the development of a demonstrator of a stakeholder-based information product in the context of a modern combat aircraft. Read more about November 2011 P8 - Development of Information System for e-Maintenance Solutions within the Aerospace Industry by www.ijpe-online.com

  • 179.
    Candell, Olov
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Karim, Ramin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Söderholm, Peter
    eMaintenance - information logistics for maintenance support2009Ingår i: Robotics and Computer-Integrated Manufacturing, ISSN 0736-5845, E-ISSN 1879-2537, Vol. 25, nr 6, s. 937-944Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Today‟s providers of maintenance and in-service support related to modern aircraft are facing major challenges. A central problem with Maintenance, Repair and Overhaul (MRO) as well as support of aircraft and other complex technical systems, is to manage the ever-increasing information flow and system complexity. Both military and commercial operators need to reduce aircraft downtime and maintenance man hours. Increased manual information management has the opposite effect, inducing unnecessary cost and affect efficiency negatively. Organisations developing and providing maintenance support products and in-service support does also need to improve the capability to efficiently exploit the increasing amount of digital product information and design data provided together with hardware (HW) and software (SW) products from aircraft manufacturers, sub-system suppliers and Original Equipment Manufacturers (OEM). One way to increase aircraft availability and improve maintenance and support efficiency, is to speed up the turnaround time for scheduled and unscheduled maintenance. The ultimate goal is risk-based utilisation and support, where true Condition-Based Maintenance (CBM) is integrated with current operational requirements and available resources in real-time. This aims at the elimination of all preventive scheduled maintenance based on fixed time intervals and execution of only corrective maintenance that has been predicted and turned into scheduled maintenance facilitated by proper support. To address the challenge of information logistics of digital product data and information within maintenance in-service support, providers need to adapt new methodologies and tools that enable full utilisation of the advantages of digital product data and information in processes and business models, e.g. Service-Oriented Architecture (SOA). In order to implement such improved support solutions in a global support environment, eMaintenance is seen as one important building block. eMaintenance includes monitoring, collection, recording and distribution of real-time system health data, maintenance generated data as well as other decision and performance support information to different stakeholders independent of organization or geographical location, 24 hours a day, 7 days a week (24/7). eMaintenance has the potential to improve the management and performance of activities related to the whole maintenance process, and thereby improve the dependability, safety and Life Cycle Cost (LCC) of critical systems. This can be realized through a coordinated application of Information & Communication Technology (ICT) throughout the maintenance and support processes, thus integrating Built-in Test (BIT) systems, external tests at different maintenance echelons, technical information, diagnostics, prognostics and other sources of support information. The purpose of this paper is to present some results from a joint academic and aerospace industry research project, describing requirements and expectations that are important in a global support environment, and also to propose some central components in an eMaintenance framework that integrates maintenance and ICT perspectives.

  • 180.
    Candell, Olov
    et al.
    Saab Aerotech, Linköping.
    Karim, Ramin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Server-oriented information logistics as support to intelligent transport services2010Ingår i: 16th World Congress and Exhibition on Intelligent Transport Systems 2009: 16th ITS World Congress ; Stockholm, Sweden, 21 - 25 September 2009, Curran Associates, Inc., 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today‟s society is dependent on an increasing volume of transportation services, which contributes to escalating requirements on economy, dependability, safety, and sustainability of applied transportation systems. When dealing with complex transportation systems with long life cycles, maintenance is fundamental to ensure these critical requirements. The increasing requirements and the technological development have also lead to the emerging approach of eMaintenance, which applies innovative Information & Communication Technology (ICT) to achieve effective information logistics for maintenance purposes. This paper describes the role and development of service-oriented eMaintenance solutions to enable intelligent transportation services and some related research efforts within railway and aviation.

  • 181.
    Candell, Olov
    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 customer and product support perspective of e-maintenance2006Ingår i: Condition Monitoring and Diagnostic Engineering Management: COMADEM 2006 ; proceedings of the 19th international congress, Luleå, Sweden, 12 - 15 June 2006 / [ed] Uday Kumar, Luleå: Luleå tekniska universitet, 2006, s. 243-252Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today the providers of customer and product support related to military aircraft are facing major challenges. Traditionally, aircraft systems have stringent requirements on safety. In addition to this, the requirements on dependability, costs, and security have increased in importance. These changes, together with an increased diversity of customer requirements in a global utilization environment, add to the complexity of providing appropriate support solutions. The increased customer requirements have also lead to concepts such as total solution selling, or functional products, where the customers are offered availability performance to a fixed price. In order to enable efficient support solutions in a global support environment, e-Maintenance is seen as one important building block. e-Maintenance includes monitoring, collection, and distribution of realtime system health data and information to all stakeholders independent of organizational belonging or geographical location, 24 hours a day, 7 days a week (24-7). The concept of e-Maintenance is realized through the application of Information & Communication Technology (ICT), which integrates built-in tests, external tests at different maintenance echelons, and other sources of support information. The purpose of this paper is to describe important requirements and expectations that a provider of customer and product support related to military aircraft systems has on e-Maintenance in a global support environment.

  • 182.
    Castaño, Miguel
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Carlson, Johan E.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Rantatalo, Matti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Risberg, Robert
    Creo Dynamics AB.
    Weston, Miles
    TWI Technology Centre Wales.
    3D Synthetic Aperture Imaging Using a Water-Jet Coupled Large-Aperture Single Transducer2014Konferensbidrag (Övrigt vetenskapligt)
  • 183.
    Castaño, Miguel
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Carlson, Johan E.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Rantatalo, Matti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Risberg, Robert
    Creo Dynamics AB.
    Weston, Miles
    TWI Technology Centre Wales.
    3D Synthetic Aperture Imaging Using a Water-Jet Coupled Large-Aperture Single Transducer2014Konferensbidrag (Övrigt vetenskapligt)
  • 184.
    Castaño, Miguel
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Carlson, Johan E.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Rantatalo, Matti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Weston, Miles
    TWI Technology Centre Wales.
    Risberg, Robert
    Creo Dynamics AB.
    3D Synthetic Aperture Imaging Using a Water-Jet Coupled Large Aperture Single Transducer2014Ingår i: 2014 IEEE International Ultrasonics Symposium (IUS 2014): Chicago, Ill. 3-6 September 2014, Piscataway, NJ: IEEE Communications Society, 2014, s. 1372-1375Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a technique for in-situ non-destructive testing of materials with applications in railway crossings. The novelty is in successfully applying the Virtual Source (VS) concept using water jet coupling for a large transducer. By focusing the sound field at the surface of the sample, the water jet probe can be built with a small nozzle opening, limiting the water consumption and making it viable for field applications. The annular geometry of the large transducer ensures the spherical wavefront assumed in the application of the SAFT algorithm, which usually limits the size of the transducer

  • 185.
    Chattopadhyay, G.
    et al.
    Queensland University of Technology.
    Kumar, Saurabh
    Larsson-Kråik, Per-Olof
    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.
    Estimation of parameter for rail degradation2006Ingår i: Condition Monitoring and Diagnostic Engineering Management: COMADEM 2006 ; proceedings of the 19th international congress, Luleºa, Sweden, 12 - 15 June 2006 / [ed] Uday Kumar, Luleå: Luleå tekniska universitet, 2006, s. 605-612Konferensbidrag (Refereegranskat)
    Abstract [en]

    Rail degradation is a significant problem for rail industries. Wear and fatigue comprises major component of rail degradation. It depends on operational conditions such as train speed, axle load, rail-wheel material type, size and profile, track construction, characteristics of bogie type, Million Gross Tonnes (MGT), curvature, traffic type, weather and environmental conditions. Development of prediction model related to those defects leading to rail breaks and/or rail replacements is vital for economic and safe operation of rail services. Estimation of parameter for failure models is necessary for accurate prediction of expected number of rail defects over a period of time based on Million Gross Tonnes (MGT) traffic, operating conditions and maintenance strategies. This paper focuses on collection and analysis of field data for various defects developed in rail track over a period of time for estimation of parameter for models predicting degradation of rails.

  • 186.
    Chattopadhyay, G.
    et al.
    Faculty of Science Engineering and Health, CQ University, Gladstone Campus.
    Parida, Aditya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Work integrated blended learning for improvement by asset managers2010Ingår i: 23rd International Congress on Condition Monitoring and Diagnostic Engineering Management: COMADEM 2010; Nara; 28 June 2010 through 2 July 2010 / [ed] Susumu Okumura, Hikone: Sunrise Publishing , 2010, s. 95-101Konferensbidrag (Refereegranskat)
    Abstract [en]

    Work integrated blended learning for asst managers is targeted to the senior engineers and managers. Main purpose of this blended learning is to enhance asset management skills in establishing and managing capital intensive assets and infrastructures. A course in asset management systems in line with PAS55 was developed to reflect the best known practices in asset management, to cover some long-term but little understood issues, and to deliver it in such a way that it was highly effective from the point of view of industries, participants and the delivery team. It includes establishing asset management systems and standards, and taking effective decisions considering asset maintenance costs, risks and performance. This paper is to outline the needs of target audience and provide overview of the work integrated blended course for asset management system for improving decision making by asset managers

  • 187.
    Chattopadhyay, Gopi
    et al.
    Central Queensland University.
    Kumar, Saurabh
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Parameter estimation for rail degradation model2009Ingår i: International Journal of Pedagogy, Innovation and New Technologies, ISSN 0973-1318, E-ISSN 2392-0092, Vol. 5, nr 2, s. 119-130Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wear and fatigue in rails are major contributors of rail degradation depending on operational conditions, track, characteristics of bogie type, Million Gross Tonnes (MGT), curvature, traffic type and environmental conditions. Estimation of parameter for failure models is necessary for accurate prediction of expected number of rail defects over a period of time based on MGT of traffic and operating conditions for developing cost effective maintenance strategies. This paper focuses on collection and analysis of field data over a period of time for estimation of parameter for modelling rail life.

  • 188.
    Chen, Jiayu
    et al.
    Beihang University, Beijing, China.
    Zhou, Dong
    Beihang University, Beijing, China.
    Guo, Ziyue
    Beihang University, Beijing, China.
    Lin, Jing
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    LYU, Chuan
    Beihang University, Beijing, China.
    LU, Chen
    Beihang University, Beijing, China.
    An Active Learning Method Based on Uncertainty and Complexity for Gearbox Fault Diagnosis2019Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 9022-9031Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is crucial to implement an effective and accurate fault diagnosis of a gearbox for mechanical systems. However, being composed of many mechanical parts, a gearbox has a variety of failure modes resulting in the difficulty of accurate fault diagnosis. Moreover, it is easy to obtain raw vibration signals from real gearbox applications, but it requires significant costs to label them, especially for multi-fault modes. These issues challenge the traditional supervised learning methods of fault diagnosis. To solve these problems, we develop an active learning strategy based on uncertainty and complexity. Therefore, a new diagnostic method for a gearbox is proposed based on the present active learning, empirical mode decomposition-singular value decomposition (EMD-SVD) and random forests (RF). First, the EMD-SVD is used to obtain feature vectors from raw signals. Second, the proposed active learning scheme selects the most valuable unlabeled samples, which are then labeled and added to the training data set. Finally, the RF, trained by the new training data, is employed to recognize the fault modes of a gearbox. Two cases are studied based on experimental gearbox fault diagnostic data, and a supervised learning method, as well as other active learning methods, are compared. The results show that the proposed method outperforms the two common types of methods, thus validating its effectiveness and superiority.

  • 189.
    Chi, Zhexiang
    et al.
    Department of Industrial Engineering, Tsinghua University, Beijing, China.
    Lin, Jing
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Chen, Ruoran
    Department of Industrial Engineering, Tsinghua University, Beijing, China.
    Huang, Simin
    Department of Industrial Engineering, Tsinghua University, Beijing, China.
    Data-driven approach to study the polygonization of high-speed railway train wheel-sets using field data of China’s HSR train2019Ingår i: Measurement, ISSN 0263-2241, E-ISSN 1873-412XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Environmental factors, like seasonality, have been proved to exert significant impact on reliability of China high-speed rail train wheels in this article. Most studies on polygonization of train wheels are based on physical models, mathematical models or simulation systems. Normally, characteristics and mechanisms of wheel polygonization are studied under ideal conditions without considering the impact of the environment. However, in practical use, there are many irregular wear wheels and irregular wear cannot be explained by theoretical models with assumptions of ideal conditions. We look at two possible factors in polygonization: seasonality and proximity to engines. Our analysis of field data shows the environmental factor has more impact on wheel polygonization than the mechanical factor. Based on the Bayesian models, the mean time to failure of the wheels under different operation conditions is conducted. A case study of China’s HSR train wheels is conducted to confirm the finding. The case study shows the degree of polygonal wear is much more severe in summer than other seasons. The finding may give a totally new research perspective on polygonization of train wheels. We use Bayesian analysis because this method is useful for small and incomplete data sets. We propose three Bayesian data-driven models.

  • 190. Chi, Zhexiang
    et al.
    Yang, Lijian
    Lin, Jing
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Huang, Simin
    Prognostics of polygonalization of highspeed railway(HSR) train wheels using generalized additive model(GAM) smoothed by spline-backfitted kernel2019Konferensbidrag (Refereegranskat)
  • 191.
    Chirumalla, Koteshwar
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Bertoni, Alessandro
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Parida, Aditya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Johansson, Christian
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Bertoni, Marco
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Performance measurement framework for product-service systems development: a balanced scorecard approach2013Ingår i: International Journal of Technology Intelligence and Planning (IJTIP), ISSN 1740-2832, E-ISSN 1740-2840, Vol. 9, nr 2, s. 146-164Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The paper proposes a framework for analysing the performances of product-service systems (PSSs) development processes using a balanced scorecard (BSC) as an instrument to guide the implementation and the evaluation of new methods and tools. Emerging from a case study in the aerospace industry, the paper discusses the main challenges in PSS development and proposes a performance measurement framework for PSS development based on multi-criteria indicators. Finally, the benefits of a framework for PSS development performance measurement are discussed.

  • 192.
    Dandotiya, Rajiv
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Decision support models for the maintenance and design of mill liners2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Gruvindustrin är beroende av att deras maskiner fungerar dygnet runt i krävande miljöer. Autogena (AG) kvarnar som används i gruvor och anrikningsverk är exempel på viktiga flaskhalsar när det gäller stillestånd, vilket direkt påverkar produktionen. Insidan av dessa kvarnar är täckta av gummiinfodring för att förhindra slitage av kvarnarna och för att optimera deras kapacitet och malningsförmåga. Eftersom infodringen nöts kontinuerligt på grund av malningen, och produktionsstopp är väldigt kostsamma, måste reparation, underhåll och inspektion av infodringen genomföras vid lämpliga tillfällen. Vid inspektionerna mäts slitaget på infodringen och det är därmed väsentligt att mätutrustningen är både tillräckligt noggrann och så snabb som möjligt för att minska stilleståndskostnaderna och så att rätt underhållsbeslut kan fattas. I denna avhandling har bland annat en metod utvecklats för att välja optimala mätmetoder för denna applikation. Slitaget av infodringen påverkar hela produktionskapaciteten och effektiviteten hos kvarnarna. Därmed påverkar underhållsbesluten om infodring inte bara kostnader för infodring och produktionsförlustkostnader utan även det totala utbytet vilket visar sig i form av variationer i hur mycket värdefull metall som finns i materialet som lämnar kvarnarna. Därför måste hänsyn tas till kvarnarnas prestanda som funktion av tiden, när beslutsmodeller utvecklas för optimala bytesintervaller. Variationer i malmegenskaper påverkar också slitaget av infodringarna och värdet av malmen. Alla dessa parametrar inverkar på kostnads- och utbytesparametrarna. Därför leder ett hänsynstagande av malmegenskaper i livscykelvinstformuleringen (LCPformuleringen) till att effektivare underhållsbeslut kan fattas. En modell för att stödja underhållsbeslut har därför utvecklats för att möta specifika krav från process-, inköps- och underhållsavdelningarna hos gruvföretaget. Livslängden hos olika komponenter i infodringen, på grund av slitage, varierar beroende på malningsprocessen i kvarnarna och de behöver stoppas vid många tillfällen för byte av infodringskomponenter. Dessa stopp är en av huvudorsakerna till stillestånd i kvarnarna vilket ger produktionsförluster som kan minimeras genom en effektiv planläggning av infodringsbytena och optimal gruppering av de detaljer som skall bytas. Denna planläggning är naturligtvis beroende av livslängden på infodringen. Livscykelkostnaden (LCC) kan reduceras ytterligare genom att på ett optimalt sätt välja infodring med längre livslängd. En modell för beslutsstöd har därför utvecklats som grupperar de olika infodringsdetaljerna på ett optimalt sätt vid byten och som med hänsynstagande till att bättre komponenter har ökade inköpskostnader, föreslår med hur mycket de olika komponenterna borde förbättras för att LCC skall minimeras. Denna modell har visat att betydande besparingar kan göras, om modellen tillämpas fullt ut och ersätter nuvarande underhållsstrategier. Systematiska utvärderingsmetoder och parvisa jämförelser har använts vid valet av optimala mätmetoder för geometrimätningar av infodringsdetaljer. Provtagning av tider, korrelationsstudier och simuleringsmetoder har använts vid LCP-optimeringen för att fastställa optimala bytesintervall för infodringen. En ansats som bygger på en totalgenomgång av alla tänkbara bytesalternativ har använts för att fastställa optimala grupperingar av infodringsdetaljer vid byte, och för att ta fram förslag på optimala livslängdsförbättringar på komponenterna.

  • 193.
    Dandotiya, Rajiv
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Mathematical model for optimum replacement interval of grinding mill liners2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents an approach to decide a cost effective replacement intervals for the liners of a grinding mill used in ore processing plants. The replacement model is based on the detailed analysis of mill performance characteristics, mill failure statistics and maintenance of mill liner. The model formulation for optimum replacement and mill efficiency includes the cost and revenue drivers for the mill. The developed decision model incorporates maintenance cost and monetary gain by doing analysis of production performance of the mill.The developed mathematical model uses the various types of process data i.e. power consumption, mill load, feed flow, metal recovery etc. which is analyzed to establish correlation with life cycle of mill liners. Due to lack of process data for some particular ore types, various techniques such as smoothing, interpolation, simulation and distribution analysis are used to generate the data for the periods for which data is not available. The paper also discusses practical problems encountered while modeling of the real data using classical approach for replacement decisions. The main objective of this paper is to develop a decision support model for taking a cost effective optimum replacement interval for mill liners. A case study was carried out on real data obtained from an ore dressing plant to validate the model.

  • 194.
    Dandotiya, Rajiv
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Banerjee, Rabindra Nath
    Indian Institute of Technology, Kharagpur.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Parida, Aditya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Optimal pricing and terminal location for a rail-truck intermodal service: a case study2011Ingår i: International Journal of Logistics, ISSN 1367-5567, E-ISSN 1469-848X, Vol. 14, nr 5, s. 335-359Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To be competitive with other modes of transport, the railway needs to be cost-effective. In order to become more competitive in the logistics industry, Indian Railways has taken new initiative to improve their operations in recent years. A rail-truck intermodal transportation service for Indian Railways is described in this paper. The main focus of the present research is to optimize the freight rate and terminal location together, in order to minimize the total shipping cost of truckers while ensuring the targeted profit of the railway. A model has been developed for the determination of the optimal freight rate and the corresponding intermodal terminal location. The key regulators of this model are the price sensitivity of the trucker and profit guarantee for railways. A case study was developed on the Delhi - Mumbai freight corridor. An analysis was performed to gain insight into the trade-offs among shipment cost and terminal locations.

  • 195.
    Dandotiya, Rajiv
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Berglund, Filip
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Increased production systems effectiveness through condition monitoring and prognostics2011Konferensbidrag (Övrigt vetenskapligt)
  • 196. Dandotiya, Rajiv
    et al.
    Fuqing, Yuan
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Optimal maintenance decision for line reparable units (LRU) for an aircraft system: a conceptual approach2008Ingår i: Quarterly Journal of the Operational Research Society of India (OPSEARCH), ISSN 0030-3887, E-ISSN 0975-0320, Vol. 45, nr 3, s. 291-302Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Maintenance decisions concerning repair of the Line Replaceable Unit (LRU) of an aircraft fleet need to be considered carefully while deciding the phasing out of the fleet. This is important for achieving higher degree of cost effectiveness and fleet availability at desired level. Discard rate and phasing out period for an aircraft fleet are the critical parameters for determining optimum time to stop the maintenance of LRU. The economic value of remaining useful life of an aircraft fleet should be taken into consideration by salvaging the LRU at the end of the phasing out. The paper suggests a methodology to arrive the time that will minimize the total life cycle cost and provide us economic basis to withdraw the maintenance resources. A mathematical model has been developed for the discard rate of aircrafts based on failure rate, mission life and remaining useful life of the aircrafts in the fleet. This will assist in fulfilling the managing demand of LRU while phasing out of the aircraft fleet.

  • 197.
    Dandotiya, Rajiv
    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.
    Economic model for maintenance decision: a case study for mill liners2012Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 18, nr 1, s. 79-97Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose – Wear life of mill liners is an important parameter concerning maintenance decision for mill liners. Variations in process parameters such as different ore properties due to the use of multiple ore types influences the wear life of mill liners whereas random order of processing, processing time and monetary value of different ore types leads to variation in mill profitability. The purpose of the present paper is to develop an economic decision model considering the variations in process parameters and maintenance parameters for making more cost effective maintenance decisions. Methodology/approach – Correlation studies, experimental results and experience of industry experts are used for wear life modeling whereas simulation is used for maximizing mill profit to develop economic decision model. The weighting approach and simulation have been considered to emphasize the contribution of parameters such as ore value and processing time of a specific ore type to a final result. Findings – This study resulted in developing an economic decision support model for mill liner replacement considering the influence of the variation in the process parameters and its affect on maintenance decisions. This study identified the various important process and maintenance parameters and described the influence of variations in the process parameters on decisions model. The results obtained from the model show that an optimum maintenance policy can only not reduce the maintenance cost, but also affect the process performance, which leads to significant improvement in the savings of the ore dressing mill. Originality and Value – The developed model considers the economic influence of ore properties, variation in process parameters and proposed an approach for considering these parameters in decision making which enhance its value in terms of increased mill profit. Practical implications – The proposed economic decision model is practically feasible and can be implemented within the ore dressing mill industries. Using the model, the cost effective maintenance decision can increase the profit of the organization significantly. Paper type – Case study Keywords: Economic model; Replacement decision; Mill liners; Ore properties; Optimization; Process parameters

  • 198.
    Dandotiya, Rajiv
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Parida, Aditya
    Nordström, Jakob
    LTU.
    A systematic evaluation of devices for measuring abrasive wear of mill liners2009Ingår i: 22nd International Congress on Condition Monitoring and Diagnostic Engineering Management: COMADEM 2009 ; June 9 - 11, 2009, San Sebastian, Spain, Miramar Palace / [ed] Aitor Arnaiz, Eibar: Fundaci n Tekniker , 2009, s. 419-427Konferensbidrag (Refereegranskat)
    Abstract [en]

    Inspection of the liner wear in the mill of an ore dressing plant is one of the critical parameters in the context of mill downtime and production performance. The total downtime cost during measurement can be reduced by a significant fraction by using appropriate measurement devices. Due to the different quality dimensions of a measuring device, e.g. the cost, accuracy, reliability and accessibility, it is necessary to select an appropriate device based on the specific needs of the industry. Customer satisfaction is perhaps the most important performance measure for the service quality of the device, and therefore this paper provides an approach to define the customer satisfaction with reference to the mentioned quality dimensions. The main aim of this paper is to determine a unified measure or quality index for the service quality of the measurement device across all the dimensions. Each quality index will then correspond to the total predicted usability of the particular measurement method based on the industry needs. Furthermore, this study also discusses the advantages and disadvantages of existing measurement methods and proposes an indirect measurement method to reduce the downtime during inspection.

  • 199.
    Dandotiya, Rajiv
    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
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Evaluation of abrasive wear measurement devices of mill liners2011Ingår i: International Journal of COMADEM, ISSN 1363-7681, Vol. 14, nr 2, s. 3-17Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Measurement of the liner wear in the mill of an ore dressing plant is one of the critical parameters in the context of mill downtime and production performance. The total downtime cost during measurement can be reduced by a significant fraction by using appropriate measurement devices. Due to the different quality attributes of a measuring device, e.g. the cost, accuracy, reliability and accessibility, it is necessary to select an appropriate device based on the specific needs of the industry. The main aim of this study is to determine a unified measure or quality index for the service quality of the measurement device across selected attributes. Each quality index will then correspond to the total predicted usability of the particular measurement method based on the industry needs. Furthermore, this study includes test of selected measurement methods and discusses the advantages and disadvantages for the same. It also proposes a new concept of an indirect measurement method to reduce the downtime during inspection.

  • 200.
    Darbari, Jyoti D.
    et al.
    Department of Operational Research, University of Delhi, India.
    Agarwal, Vernika
    Department of Operational Research, University of Delhi, India.
    Yadavalli, Venkata S.S.
    Department of Industrial and Systems Engineering, University of Pretoria, South Africa.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jha, Prakash C.
    Department of Operational Research, University of Delhi, India.
    A multi-objective fuzzy mathematical approach for sustainable reverse supply chain configuration2017Ingår i: Journal of Transport and Supply Chain Management, ISSN 2310-8789, E-ISSN 1995-5235, Vol. 11, artikel-id a267Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Designing and implementation of reverse logistics (RL) network which meets the sustainability targets have been a matter of emerging concern for the electronics companies in India.

    Objectives: The present study developed a two-phase model for configuration of sustainable RL network design for an Indian manufacturing company to manage its end-of-life and endof-use electronic products. The notable feature of the model was the evaluation of facilities under financial, environmental and social considerations and integration of the facility selection decisions with the network design.

    Method: In the first phase, an integrated Analytical Hierarchical Process Complex Proportional Assessment methodology was used for the evaluation of the alternative locations in terms of their degree of utility, which in turn was based on the three dimensions of sustainability. In the second phase, the RL network was configured as a bi-objective programming problem, and fuzzy optimisation approach was utilised for obtaining a properly efficient solution to the problem.

    Results: The compromised solution attained by the proposed fuzzy model demonstrated that the cost differential for choosing recovery facilities with better environmental and social performance was not significant; therefore, Indian manufacturers must not compromise on the sustainability aspects for facility location decisions.

    Conclusion: The results reaffirmed that the bi-objective fuzzy decision-making model can serve as a decision tool for the Indian manufacturers in designing a sustainable RL network. The multi-objective optimisation model captured a reasonable trade-off between the fuzzy goals of minimising the cost of the RL network and maximising the sustainable performance of the facilities chosen.

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