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  • 201.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. systemekonomi.
    Maintenance from Different Perspectives: Total Quality Maintenance (TQMain) for a Comprehensive Asset Maintenance2008In: ICOMS 2008 Conference Proceedings, Asset Management Council, Surrey Hills, Australia , 2008, p. 37/1-8Conference paper (Refereed)
    Abstract [en]

    Due to the interactions between the working areas involved in a production process, such as operation, quality, management, working environment, LCC management and analysis and maintenance, problems in these working areas are usually complex. It is well-known that maintenance is influenced by and influences these working areas. Maintenance role can be described technically using; failures, downtime, availability, planned stoppages, etc. or economically using; direct cost of maintenance, maintenance cost to production cost, spare part cost, etc. In order to high light maintenance technical and economic role and quantify its impact on company profitability and competitiveness, it is necessary to cover all relevant working areas within plant where maintenance affect. Thus, maintenance should be considered from different perspectives due to its interplay with the working areas involved in the production process. In this paper, maintenance is recognised as a means for maintaining the quality of the working areas involved in a production process at a continuous reduced cost. Also, we introduce maintenance from different perspectives based on its role in company profitability and competitiveness. Further more, the paper give big attention to introduce and discuss Total Quality maintenance (TQMain) philosophy with respect to the maintenance broader definition. An industrial case highlights TQMain applicability & maintenance economic importance is also introduced.

  • 202.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Maintenance from Different Relevant Perspectives: Total Quality Maintenance (TQMain) for a Comprehensive Asset Maintenance2008Conference paper (Refereed)
  • 203.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Maintenance Function Deployment (MFD) for Cost-effective & Continuous Improvement of Company’s Business: Using Total Quality Maintenance (TQMain)2008Conference paper (Refereed)
  • 204.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Maintenance or Maintenance Lack which Actually Costs: A Model to Quantify the Impact of VBM on Company's Business2005In: International conference on condition monitoring, 2005, p. 15-20Conference paper (Refereed)
  • 205.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    MDSS: ett beslutsstödsystem för effektivare underhållsåtgärder  del IV:1:22011In: Bättre produktivitet : tidning för PLAN och regionala produktivitetsföreningar : med plan-nytt, ISSN 1402-1145, no 1, p. 24-25Article in journal (Other (popular science, discussion, etc.))
  • 206.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    MDSS: ett beslutsstödsystem för kostnadseffektivare underhållsåtgärder  Del IV:2:22011In: Bättre produktivitet : tidning för PLAN och regionala produktivitetsföreningar : med plan-nytt, ISSN 1402-1145, no 2, p. 24-Article in journal (Other (popular science, discussion, etc.))
  • 207.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Med färre dyra stopp kan produktionen räddas kvar2004In: Dagens industri, ISSN 0346-640X, no 0607Article in journal (Other (popular science, discussion, etc.))
  • 208.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    More Reliable Profitable and Competitive Production via Effective e-Maintenance: A Case Study2015In: Proceedings of the 7th World Congress on Engineering Asset Management (WCEAM 2012) / [ed] Woo Bang Lee,Byeongkuen Choi, Lin Ma and Joseph Mathew, Switzerland: Springer, 2015, p. 49-59Chapter in book (Refereed)
    Abstract [en]

    Profitable production demands continuously improved maintenance decision accuracy for reducing/avoiding failures and unplanned stoppages due to their consequences. More accurate decisions prolong life length of components and consequently machines, and maintain the production running longer. When a condition monitoring (CM) value exceeds a significant (warning) level it demands a clear understanding of what happened and how it will develop in the next future to avoid failures. Also, CM demands reliable information concerning the probability of failure, residual life time and when is the most profitable time of conducting maintenance. Companies strive to reduce production cost in order to increase the possibility of offering customers lower prices & generating additional competitive advantages. But, applying new technologies for enhancing maintenance and production performances and company competitiveness counter many problems in industry. In this paper, a new innovative e-Maintenance Decision Support System (eMDSS) is introduced and discussed; the problems facing successful implementation of eMDSS based on a case study are introduced and discussed. Solutions to avoid the problems facing successful implementation of e MDSS are suggested and discussed. eMDSS offers a unique opportunity to achieve just in time dynamic and cost-effective maintenance by selecting the most profitable time for maintenance. It offers innovative solutions to increase maintenance profitability by enhancing maintenance decision accuracy via:

    1. Identifying & classifying problems based on their shares in losses in production.

    2. Predicting the value of CM parameter, e.g. vibration, level in the near future.

    3. Estimating the probability of failure and component remaining life in the near future.

    4. Estimating the most profitable time for maintenance action.

    5. Selecting the most profitable maintenance action.

    6. Mapping & following up maintenance & production performances.

    7. Identifying and following up the most profitable investment in maintenance.

    eMDSS combines technical and economic data describing future situation in addition to the current & past data, which is necessary for production and maintenance successful planning. The major conclusion is that applying eMDSS it is possible to reduce failures appreciably, prolong life length of components/equipment & perform profitable maintenance

  • 209.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Mycket att tjäna på tillståndsbaserat underhåll2005Other (Other (popular science, discussion, etc.))
  • 210.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    On a graphical method for the selection of a maintenance techniqueManuscript (preprint) (Other academic)
    Abstract [en]

    In this paper a graphical method for the selection of a cost-effective monitoring technique is suggested. Also, a graphical method to estimate the level at which components should be replaced when using a cost-effective technique, i.e. threshold level, is proposed. These two methods are based on the concept of the Total Time on Test, TTT-plot on age and condition dependent replacement is discussed.

  • 211.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    On establishing cost-effective condition-based maintenance: Exemplified for vibration-based maintenance in case companies2012In: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 18, no 4, p. 401-416Article in journal (Refereed)
    Abstract [en]

    Purpose

    – The purpose of this paper is to develop the steps required for establishing and running cost-effective condition-based maintenance (CBM) exemplified for vibration-based maintenance (VBM) and compared with real implementations in case companies.

    Design/methodology/approach

    – The study is based on published knowledge and experience within condition monitoring (CM) and CBM, and three case studies.

    Findings

    – The study has shown that all three case companies are in a big need for systematic procedures for doing right things right, in the right time cost-effectively (establishing and running a cost-effective CBM).

    Research limitations/implications

    – The paper focuses on development of cost-effective CBM exemplified for VBM. Also, the case companies belong to three branches: paper and pulp mills, energy producer and engineering manufacturing. The case companies have different levels in applying CBM/VBM, experience and knowledge in CM and CBM.

    Practical implications

    – Systematic procedures for establishing CBM/VBM policy are developed, motivated and discussed in a way which enables the user to establish and run CBM/VBM policy cost-effectively.

    Originality/value

    – The steps of establishment of CBM/VBM provide a unique model for companies to establish and run cost-effective maintenance its originality.

  • 212.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    On the design of the integration of quality, maintenance and production2003In: Condition monitoring and diagnostic engineering management; COMADEM 2003 / [ed] Shirivastav, O.P. ; A-Najjar B. ; Rao, R. B.K. N., 2003, p. 23-33Conference paper (Refereed)
  • 213.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    On the effectiveness of vibration-based monitoring programsManuscript (preprint) (Other academic)
  • 214.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    On the modelling of condition dependent failure rates in mechanical systemsManuscript (preprint) (Other academic)
    Abstract [en]

    The cycle between two replacements based on condition monitoring is discussed. Models representing a condition dependent failure rate function reflecting the information in a monitoring parameter are suggested. For the selection of a cost-effective technique, a modified version of the Proportional Hazards Model, PHM, is proposed. Utilizing this modified model, it is possible to reveal the effect of monitoring parameters and operating conditions on the failure rate function. General comments on the application of the cost equation are given.

  • 215.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    On the Relation between Operating Conditions and Changes in Vibration Signature: A Case Study in Paper Mill1998Report (Other academic)
  • 216.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    On the relation between operating conditions and changes in vibration signature: A case study in paper mill machine1998In: International condition monitoring conference; 1998 technology showcase / [ed] Humphrey, G. R. ; Martin, R. W., 1998, p. 226-235Conference paper (Refereed)
  • 217.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    On the selection of condition based maintenance for mechanical systems1991In: Operational reliability and systematic maintenance / [ed] Holmberg, K; Folkeson A., London: Elsevier Applied Science , 1991, p. 153-175Chapter in book (Refereed)
    Abstract [en]

    The requirements for increased plant productivity and safety, and reduced maintenance costs, have led to an increasing interest in methods for condition monitoring of mechanical systems.  In the literature on Reliability-Centred Maintenance, RCM, the selection of a maintenance technique is mainly carried out on the level of system failure modes. Also, distinguishing criteria such as the long run average cost per unit time are not modelled see for example, Nowlan et al. (1978). In this study, a summary of three papers, Al-Najjar (1990a, b& c), component failure causes and failure mechanisms are involved in the selection problem, and a long run average cost per unit time is modelled. In chapter 2, the identification of significant components is described. State-changes of a component are discussed in chapter 3. New classifications of failures, monitoring parameters and monitoring techniques are proposed in chapters 2 and 4, respectively. Data sampling and analysis are discussed in chapter 4. The cumulative sum chart is proposed as a technique to reduce the fluctuation in monitoring parameter value.   In chapter 5, the selection of a cost-effective policy is carried out based on economical and non-economical distinguishing criteria. Chapters 1 to 5 summarise Al-Najjar (1990a). Modelling of a condition dependent failure rate function is discussed in chapter 6, which the summary of Al-Najjar (1990b). Chapter 7 is addressed to the problem of selecting a cost-effective monitoring technique based on observational data. To carry out the selection, we suggest the use of a generalization of a method, related to the Total Time on Test, TTT-plot, introduced by Bergman (1977). Also, a graphical method to estimate the threshold level of a monitoring parameter when using a cost-effective technique is proposed, see also Al-Najjar (1990c).

  • 218.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Onödigt underhåll kostar företagen stora pengar2002Other (Other (popular science, discussion, etc.))
  • 219.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Prediction of the vibration level when monitoring rolling element bearings in paper mill machines2001In: International Journal of COMADEM, ISSN 1363-7681, Vol. 4, no 2, p. 19-26Article in journal (Refereed)
    Abstract [en]

    Rolling element bearings in paper mill machines are considered in this paper due to their critical role in the machine function. In general, the cost-effectiveness of a vibration-based maintenance policy mainly depends on the technical and economic effectiveness of the vibration monitoring system, i.e. software, hardware, and personnel, being used. In this paper, a model for predicting the vibration level of rolling element bearings in paper mills is developed. In the model, a combination of bearing vibration history, current condition and data from operating conditions is used to predict the vibration level of a bearing during a near future.

    The factors influencing the condition of rolling element bearings during operation are discussed. These factors are related partly to operating and environmental conditions and partly to previous changes in the condition of the bearing. The operating life of a bearing is divided into four phases characterised by their vibration behaviour. One of the important conclusions is that a mechanistic model would be more appropriate than other models for predicting the vibration level of a rolling element bearing and describing the deterioration process, which are needed to achieve better understanding of the bearing vibration behaviour.

  • 220.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Prediction of the vibration level when monitoring rolling element bearings in paper mills machines1998Conference paper (Refereed)
  • 221.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Product quality problems can be detected earlier by vibration spectral analysis than by traditional quality control diagram: A case study2000Conference paper (Refereed)
  • 222.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Project-based learning for technical education in master programms2006In: International quality in engineering education / [ed] Pudlowski, ZJ, 2006, p. 216-219Conference paper (Refereed)
    Abstract [en]

    Project-based learning methodology has been applied in a technical education Master programmes over almost the last almost nine years. The major results that have been achieved are that the graduated students have acquired a wide range of knowledge, together with deeper theoretical and practical skills in specific topics, and the effective enhancement of their analysis skills and training in constructive opposition to the examination of the research work of other groups. The main conclusion is that the course final written examination is not the only reliable examination form for judging the understanding of students. Project-based learning methodology provides a continuous examination of the gradual understanding of students instead of a final written examination.

  • 223.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Review of maintenance concepts1999Conference paper (Refereed)
  • 224.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Selection and improvment of a cost-effective maintenance policy: the case of rolling element bearings1998In: International Journal of COMADEM, ISSN 1363-7681, Vol. 1, no 2, p. 25-36Article in journal (Refereed)
    Abstract [en]

    The main result reported in this paper is that the bearing’s mean effective life could be extended appreciably if an existing vibration-based maintenance policy is used effectively. A new maintenance approach was developed to overcome some of the limitations of TPM and RCM and is based on the Deming managerial feedback cycle. It is a methodology to sustain and improve technical and economic effectiveness of the essential manufacturing process elements. It is shown that by using vibration-based monitoring, (VBM), program in the frame of a common database for a plant IT-system, the causes behind quality deviations and failures can be identified and eliminated effectively and the company’s economics would be improved. Criteria to select the most cost-effective VBM program and the most cost-effective vibration-based maintenance policy are developed. It is shown, by two case studies, that improvements in VBM systems can be achieved by effective feedback of the results of failures, renewal condition and VBM history analysis. The contribution of this study is: The development of a sequential method for the selection and improvement of a cost-effective vibration-based maintenance policy. This methodology can be used to justify, on economic criteria, the use of VBM systems to indicate when rolling element bearings should be renewed.

  • 225.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Selection of a cost-effective vibration based monitoring system1994Conference paper (Refereed)
  • 226.
    Al-Najjar, Basim
    Linköpings univeristet.
    Some problems on the selection of a condition based maintenance technique for mechanical systems1990Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the first paper we focused mainly on establishing a sequential method for the selection of a maintenance technique for mechanical systems. The selection problem is studied for the components having considerable consequences and a non-negligible failure intensity. Identification of these components based on their failure mechanisms and failure causes is discussed and a modified version of the usual Failure Modes, Effects and Criticality Analysis, FMECA is suggested. A cumulative sum chart is proposed to identify a replacement time. This is explained by way of two examples. In order to run cost per unit time is proposed. The selection of a maintenance technique based on the intrinsic information of monitoring parameters is introduced.

    Ability of a monitoring parameter in predicting failures, can be described as a probability of failure in the future conditionally on the current value of a model monitoring parameter. Thus, the second paper is focused on introducing a model relating a condition dependent failure rate to a component condition. For the selection of a cost-effective technique a modified proportional hazards model, PHM, is proposed. The modified model is able to reveal the effect of observing monitoring parameters and operating conditions on failure rate function.

    A graphical method, based on a Generalized Total Time on Test, a GTTT- plot, for the selection of a cost-effective technique is proposed in the third paper. Also, a graphical method to estimate the threshold level for a cost-effective technique based on the same concept is suggested. These methods are illustrated by way of an example.

  • 227.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strategies for Maintenance Cost-effectiveness2010In: E-maintenance / [ed] Kenneth Holmberg, London: Springer, 2010, 1, p. 297-344Chapter in book (Refereed)
    Abstract [en]

    To survive hard international competition, it is necessary for many producing companies to enhance their competition positions by, for example, reducing production costs and maintaining and improving product quality to increase the profit margin. In order to achieve these strategic goals, strategies for making maintenance more profitable are developed, introduced and discussed in this chapter. These strategies are all developed as software modules included by an innovatively new maintenance decision support system (MDSS). Also, theoretical backgrounds are introduced, and software prototypes for making the application of any of the tools on a daily basis easier and more cost-effective are developed and discussed, and their functionalities are tested. MDSS consists of three toolsets, where each toolset consists of one to three tools that can be used for different objectives and applications. It is designed to support maintenance and production engineers to achieve dynamic and cost-effective maintenance decisions. The latter will be discussed in Chapter 13. MDSS software prototype can be utilised for several objectives, such as, to:

    • enhance the accuracy of maintenance decisions;

    • simulate and select the most cost-effective maintenance solution, i.e., the best investment in maintenance;

    • identify and prioritise problem areas; and

    • map, monitor, analysis, follow up and assess maintenance contribution in company profit.

  • 228.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    System för underhållsstöd gör det lättare välja lönsammaste underhåll2011Other (Other (popular science, discussion, etc.))
  • 229.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    The impact of the lack of real-time measurements of performance parameters on vibration-based maintenance1999Conference paper (Refereed)
  • 230.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    The Lack of Maintenance and not Maintenance which Costs: A Model to Describe and Quantify the Impact of Vibration-based Maintenance on Company's Business2007In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 107, no 1, p. 260-273Article in journal (Refereed)
    Abstract [en]

    Maintenance is usually considered as a cost-centre or necessary evil, because (according to this aspect) it costs the company unnecessarily big budget, while it should be treated as a profit-generating centre. The problem addressed in this paper is that if maintenance is a profit contributor how does maintenance technical impact transfer to the plant other activities such as production, quality and tied up capital, and how can this effect ultimately influence company's profit and competitiveness?

    In this paper, we discuss maintenance role in maintaining the quality of the essential elements contribute in the manufacturing process such as production/operation and quality on the economic basis for achieving the competitive advantages desired. Interactions between maintenance, production and quality, and how simple technical effects of maintenance in the operative level can be transferred to the economic effect in the strategic level influencing company’s profitability and competitiveness is discussed. A model describes the mechanisms through which vibration-based maintenance (VBM) impact is transferred to the plant other activities and company's business is developed and verified using real and typical data based on the author’s experience in the Swedish paper mills.

    The main result of this study is developing a model for converting vibration-based maintenance technical to financial impact and assessing it. The model potential and applicability is tested using a combination of real and typical data. The result also demonstrates how the potential of the VBM impact on the production, quality, tied up capital and different relevant expenses can be assessed financially. Furthermore, the model can be utilised for two additional objectives; for examining whether the investment done in maintenance is cost-effective or not, and simulating maintenance financial impact on the relevant working areas in order to assess the investment required before selecting and applying the improvement plan. The major conclusions are; applying the model, VBM policy can be introduced as a profit centre, and identifying the transferring mechanisms of maintenance impact highlights where, why and how much should be invested in order to enhance production and maintenance performance continuously and cost-effectively.

  • 231.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    The Rockets1983 (ed. 1)Book (Refereed)
  • 232.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    The Vibration Level of Rolling Element Bearings in Paper Mill Machine1999Report (Other academic)
  • 233.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Tillämpning av PBI inom ämnet systemekonomi2001Report (Other academic)
  • 234.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Total quality maintenance: An approach for continuous reduction in costs of quality products1996In: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 2, no 3, p. 4-20Article in journal (Refereed)
    Abstract [en]

    The common thread in achieving and maintaining high Overall Equipment Effectiveness, OEE, is the availability of improved manufacturing processes capable of producing quality products without interruption. Implementing Just In Time, JIT, philosophy demands healthy processes. Any interruption of the line caused by any equipment malfunction or failure will result in a major disruption of output or even line or factory shutdown. Thus, an effective maintenance program should be evolved to provide the required availability of machinery and output quality. A new concept of condition-based maintenance, Total Quality Maintenance, TQMain, is presented. It aims to maintain not only machinery but all the elements constituting a manufacturing process, e.g. production/operation, environmental condition, personnel, methods, material, quality control. TQMain is a result of establishing a common database through integrating the maintenance program with other plant programs to form an overall plant Information Technology, IT-system. Identifying and ‘eliminating’ quality deviations and failure causes at early stages, and extensive use of data feedback are the suggested tools to accomplish continuous improvements and to assure high quality products.

  • 235.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Total Quality Maintenance for Assuring Continuous Improvement of Company’s Profitability and Competitiveness: Case Studies2006In: Condition monitoring and diagnostic engineering management: COMADEM 2006 / [ed] Kumar, U. ; Parida, A ; Rao, R. B. K. N., Luleå universitet, Luleå , 2006, p. 181-190Conference paper (Refereed)
    Abstract [en]

    Industries with intensive invested capital demands healthy processes continuously to achieve their economic goals, because any interruption of the production caused by any equipment malfunction or failure may result in a major disruption of output or even production shutdown. Thus, an effective maintenance concept should be evolved to provide the required tools, data and methods for detecting deviations at an early stage to maintain and enhance the availability of machinery, product quality and profits. A new concept of condition-based maintenance (CBM), Total Quality Maintenance (TQMain) is presented. It aims to maintain not only machines but the quality of the essential elements involved in the production process, such as methods, operational conditions, personnel competence, raw material, quality and managerial systems. The major results have achieved in this study are

    Evidence of prolonging the bearing's mean effective live by using more accurate diagnosis and prognosis are confirmed when faulty bearing installation, faulty machinery design and harsh environmental condition are considered.

    Changes in the machine speed and load influence the information delivered by vibration signals.

    Applying vibration spectral analysis, it is possible to detect the deviations in the quality of a product during the processing time and before it is completed.

    Maintenance profit of one paper machine was found to be at minimum about 3.58 MSEK yearly.

    The main conclusion is; identifying and eliminating causes behind deviations in quality and equipment condition at an early stage are vital to accomplish continuous improvements and to assure longer machine live and high quality products at competitive price. Several case studies have been conducted during the last ten years to verify the applicability and benefits of TQMain are discussed

  • 236.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Total Quality maintenance (TQMAIN) a new concept for continuous enhancing of company's economic competitiveness: case studies2002In: Proceedings IFRIMmmm: maintenance mangament & modelling conference, Växjö, 2002Conference paper (Refereed)
  • 237.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Total Time on Test, TTT-plots for Condition Monitoring of Rolling Element Bearings in Paper Mills2003In: International Journal of COMADEM, ISSN 1363-7681, Vol. 6, no 2, p. 27-32Article in journal (Refereed)
    Abstract [en]

    When using vibration-based maintenance, it is easier to detect damage in rolling element bearings. But the damage severity and risk of bearing's failure, if no maintenance action such as replacement is done, can not be assessed accurately. When the vibration level of a rolling element bearing is increasing or it is close to (or greater than) a predetermined replacement level, the assessment of the probability of a bearing’s failure enhances the decision making process. Thus, at each vibration measurement occasion a decision has to be made regarding whether the bearing needs to be maintained and how urgent it actually is.

    The paper describes a graphical method for both assessing the probability of failure of damaged rolling element bearing and predicting the residual of its effective life. It uses history of the bearing in question and life statistics as well as the vibration levels at failure/condition-based replacements of past bearings of the same design or of very similar performance and duties. This method is based on the concept of Total Time on Test, TTT-plot. The application of TTT-plot on age and condition-based maintenance techniques are discussed and described by two examples. This graphical method is developed from previous work by the author and others. 

  • 238.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Totalt kvalitetsunderhåll (TKU): Ett koncept för kvalitetssäkring och förbättring till minskande kostnader1999In: Konferensen vinnande ledarskap: den 9-10 februari 1999 på svenska mässan congress i Göteborg, 1999, p. 171-176Conference paper (Other academic)
  • 239.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    TTT-plots for CM of rolling element bearings in paper mills2000In: Proceedings systems integrity and maintenance / [ed] Mathew, J; Zhong, B, 2000, p. 62-68Conference paper (Refereed)
    Abstract [en]

    In general, it is easier to detect that some sort of damage has occurred in rolling element bearings than to accurately assess damage severity and the risk of failure if no replacement is done when using vibration-based maintenance. When the vibration level of a rolling element bearing is increasing, close to or greater than the predetermined replacement level, the assessment of the probability of a bearing's failure enhances the decision making process. Thus, at each vibration measurement a decision has to be made regarding whether the bearing needs to be replaced and how urgent it is actually. The paper describes a graphical method for both assessing the probability of failure of damaged rolling element bearing and predicting the residual of its effective life. It uses history of the bearing in question and life statistics as well as the vibration levels at failure/condition-based replacements of past bearings of the same design or very similar performing and duties. This method is based on the concept of Total Time on Test, M-plot. The application of TTT-plot on age and condition-based maintenance techniques are discussed and two examples are presented. This graphical method is developed from previous work by the author and others.

  • 240.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Vibration monitoring of rolling element bearings in paper mills: Effectiveness and improvements1998Conference paper (Refereed)
  • 241.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Vibration signal analysis as a quality assurance tool in manufacturing industry: A case study2000In: European maintenance congress; Euromaintenance 2000, 2000, p. 41-48Conference paper (Refereed)
  • 242.
    Al-Najjar, Basim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Vibration spectral analysis as a quality assurance tool: a case study2000Report (Other academic)
  • 243.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Vibration-based maintenance and common database: Effectiveness and benefits1998Conference paper (Refereed)
  • 244.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Växjö universitet utvecklar underhållsverktyg2005In: Industriprojekt, no 6, p. 30-32Article in journal (Other (popular science, discussion, etc.))
  • 245.
    Al-Najjar, Basim
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Abou Saleh, Nazih
    Damscus University.
    A Model to Identify and Prioritise the Causes behind Losses in Company profit: Application Example2010In: Damascus University Journal, ISSN 1999-7302, Vol. 26, no 2, p. 35-45Article in journal (Refereed)
    Abstract [en]

    A production process includes several sub-processes (working areas) that are responsible for performing the different tasks required to accomplish the mission of the process. Thus, it is important to avoid a shortage of resources, unplanned stoppages and idle times that may arise. The problem addressed in this paper is: How should maintenance be considered in conjunction with plant activities, such as production, quality and personnel competence for easily and effectively identifying and quantifying company losses in profitability and eliminating underlying causes? In this paper, the interactions between major working areas have been introduced and discussed. The major result achieved in this study is the development of a new model (Maintenance Function Deployment (MFD), for an easy and effective identification and quantification of company losses in profitability. Four matrixes have been used for developing MFD model for effectively integrating maintenance with production, competence and quality. An application example is conducted to demonstrate the possibility of applying the model and its potential for enhancing production processes profitably. The main conclusion is: applying MFD gives an enormous opportunity to continuously maintain the quality of the working areas under consideration, which makes MFD one of the company’s objective-driven tools for enhancing its profitability and competitiveness.

  • 246.
    Al-Najjar, Basim
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Algabroun, Hatem
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    A Model for Increasing Effectiveness and Profitability of Maintenance Performance: A Case Study2016In: Proceedings of 2016 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (QR2MSE 2016) 2016 World Congress on Engineering Asset Management (WCEAM2016), Institute of Reliability Engineering , 2016, p. 1-7, article id QR2MSE2016 & WCEAM2016-0003-0038Conference paper (Refereed)
    Abstract [en]

    In today’s market, companies strive to achieve the competitive advantages. Failing in achieving these goals could threaten the companies’ existence. Failures in the operative level impact negatively on achieving these goals. In order to record these failures for better actions planning, special systems are often used for counting the number of failures, registering the duration of machines downtime and uptime for assessing the total downtime and classifying problems/failures in categories that are decided in advance. These categories can be Electrical, Electronic, Hydraulic, Mechanical, Pneumatics, Human error, and Miscellaneous. In this study, we develop a model to break down the contents of a company/machine failure databases, prioritize failures, assess economic losses due to failure impact on the competitive advantages and suggest a method of how maintenance actions should be rank-ordered cost-effectively. The model is tested using real data. The major results showed that losses aremainly due to two categories i.e. “Bad quality“ and “Less profit margin”, where failures of “Gear”, “Bearing” and “Raw materials quality” cause most of the losses. It is concluded that this model enables the user to quickly identify and prioritize maintenance and improvement efforts cost-effectively.

  • 247.
    Al-Najjar, Basim
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Algabroun, Hatem
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    A Model for Increasing Effectiveness and Profitability of Maintenance Performance: A Case Study2018In: Engineering Asset Management 2016: roceedings of the 11th World Congress on Engineering Asset Management, Switzerland: Springer, 2018, p. 1-12Conference paper (Refereed)
    Abstract [en]

    In today’s market, companies strive to achieve the competitive advantages.Failing in achieving these goals could threaten the companies’ existence.Failures in the operative level impact negatively on achieving these goals. In orderto record these failures for better actions planning, special systems are often usedfor counting the number of failures, the duration of machines downtime and uptimefor assessing the total downtime and classifying problems/failures in categories thatare decided in advance. In this study, we develop a model to break down thecontents of a company failure databases, prioritize failures, assess economic lossesdue to failure impact on the competitive advantages and suggest a method of howmaintenance actions should be rank-ordered cost-effectively. The model is testedusing real data. The major results showed that losses are mainly due to twocategories i.e. “Bad quality” and “Less profit margin”, where failures of “Gear”,“Bearing” and “Raw materials quality” cause most of the losses. It is concluded thatthis model will enable the user to quickly identify and prioritize maintenance andimprovement efforts cost-effectively.

  • 248.
    Al-Najjar, Basim
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Alsyou, Imad
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Mechanistic model for predicting the vibration level: A case study2004In: Proceedings of MIMAR 2004 - 5th IMA International Conference on Modelling in industrial maintenance and reliability: Impact on practice, 2004, p. 7-12Conference paper (Refereed)
  • 249.
    Al-Najjar, Basim
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Alsyouf, Imad
    Enhancing a Company’s Profitability and Competitiveness Using Integrated Vibration-Based Maintenance: A Case Study2004In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 157, no 3, p. 643-657Article in journal (Refereed)
    Abstract [en]

    In this paper a model is developed for identifying, monitoring and improving the economic impact of vibration-based maintenance (VBM). This model provides an additional possibility of identifying where, why and how much capital should be invested, and judges whether or not the investment was cost-effective. The model is further utilised to develop relevant maintenance performance measures. When the model was tested in a Swedish paper mill, the main results were: the average yearly maintenance profit achieved using integrated VBM was at least 3.58 million Swedish kronor (SEK) (approximately USD 0.358 million), and average potential savings (economic losses) were around SEK 30 million (USD 3 million). Furthermore, the model facilitated identification of problem areas and recognition of where investments should be made. The major conclusion is that the better the data coverage and quality, the greater control is possible over direct maintenance costs, savings and further profits in maintenance. Moreover, using the model it would be easier and more reliable to detect deviations in the maintenance performance and eliminate their causes at an early stage.

  • 250.
    Al-Najjar, Basim
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Alsyouf, Imad
    Improving Effectiveness of Manufacturing Systems using Total Quality Maintenance2000In: Integrated Manufacturing Systems, ISSN 0957-6061, E-ISSN 1758-583X, Vol. 11, no 4, p. 267-276Article in journal (Refereed)
    Abstract [en]

    In manufacturing systems intelligent techniques are being used to integrate and interpret data from multiple sensors to predict tool wear and tool life. Less attention is devoted to developments of integrated condition monitoring systems, which enable the user to evaluate a multi-variant system based on the data collected from, e.g. maintenance, quality, production, etc.

    In this paper we discussed different approaches of how to keep availability, quality, and productivity at high levels. Also, we proposed a new approach for expert system concept, which is characterised by using total quality maintenance (TQMain.) concept; having a common database, and continuously improved knowledge base with intelligent inference engine.  It can enhance data reliability, decision making certainty, remove the redundancy in monitoring systems, and allow the user to detect and eliminate reasons behind variations through effective diagnosis and prognosis. This will enhance the performance-efficiency, availability and quality rate, i.e. overall equipment effectiveness of the manufacturing systems.

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