Journal of Quality in Maintenance Engineering

Observations of acoustic emission in a hydrodynamic bearing : Table of Contents

S. Ali Mirhadizadeh, D. Mba — Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – Numerous studies have been conducted in the field of acoustic emission (AE) technology applied to rotating machine fault diagnosis. Principally, most of the work to date has been focused on correlating AE activity to the defect condition on rolling element bearings with limited investigations on hydrodynamic bearings. This paper aims to address this issue. Design/methodology/approach – This paper presents experimental tests aimed at understanding the influence of speed and load on generation of AE in a hydrodynamic bearing. Findings – The research presented shows that the power losses associated which hydrodynamic bearing has a direct influence on the generation of AE. Research limitations/implications – Further research should include the application of the proposed methodology on a broad range of operational machines employing hydrodynamic bearings. Practical implications – In developing the AE technology for monitoring hydrodynamic bearings operated under variable speed and load conditions, it is essential that a relationship between the operational variables and the generation of AE is established, and this paper explores such a relationship. Originality/value – The paper presents the first known correlation between AEs and the operating parameters of a hydrodynamic bearing.

Classification and cost analysis of switches and crossings for the Swedish railway: a case study : Table of Contents

Arne Nissen — Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – Switches and crossings (S&Cs) are an important component of Banverket's (the Swedish National Rail Administration's) infrastructure and are associated with 13 per cent of the total maintenance cost. Therefore, it is important that a detailed study of different aspects of the costs of S&Cs should be undertaken to analyze individual maintenance costs. This will in the future give the possibility of enhancing the management of infrastructure. Design/methodology/approach – A case study is undertaken to study, identify and classify the costs of S&Cs for Banverket. Data are taken from Banverket's maintenance information systems and accounting system. Findings – A rough estimation of the cost for individual S&Cs can be identified in this way. The cost varies very much and a more detailed study is needed to validate the cost on this level. The average cost of a group of S&Cs varies less and is therefore more likely to reflect the true cost. The cost varies depending on the amount and type of traffic. Moreover, the type of S&C seems to reflect the cost variation, but further investigation is needed to verify this conclusion. Research limitations/implications – The accounting system does not store data for individual assets, and further research would be more fruitful if individual costs could be recorded by the entrepreneur. Larger repairs should be separated from annual maintenance tasks in a future study. Data from this study could be used to build a life cycle cost model for S&Cs. Practical implications – Cost identification is a first step in finding a way to organize maintenance in a more cost-effective way. Originality/value – The paper shows a way to distribute costs (in the accounting system) down to individual subsystems of the infrastructure. This enables analysts to find cost drivers and plan for modification of or reinvestment in the asset.

The maintenance management framework: A practical view to maintenance management : Table of Contents

Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – The purpose of this paper is to define a process for maintenance management and to classify maintenance engineering techniques within that process. Design/methodology/approach – The paper presents a generic model proposed for maintenance management which integrates other models found in the literature for built and in-use assets, and consists of eight sequential management building blocks. The different maintenance engineering techniques are playing a crucial role within each one of those eight management building blocks. Following this path it characterizes the “maintenance management framework”, i.e. the supporting structure of the management process. Findings – The paper offers a practical vision of the set of activities composing each management block, and the result of the paper is a classification of the different maintenance engineering tools. The discussion of the different tools can also classify them as qualitative or quantitative. At the same time, some tools will be very analytical tools while others will be highly empirical. The paper also discusses the proper use of each tool or technique according to the volume of data/information available. Practical implications – As a consequence, of the implementation of advanced manufacturing technologies and just-in-time production systems, the nature of the production environment has changed during the last two decades. This has allowed companies to massively produce products in a customized way. But the increase in automation and the reduction in buffers of inventory in the plants clearly put more pressure on the maintenance system. The present maintenance management framework has been proposed in order to diminish this pressure. Whatever the model an organization adopts, it has to be evolving to continue being useful against the fast changes that occur in business, communications and industry. A key to achieve this could be the incorporation of the techniques proposed in this paper besides the integration of platforms known as “next generation manufacturing practices” This implies the use of e-maintenance as a sub-concept of e-manufacturing and e-business. Originality/value – This paper presents not only a process but also the framework and techniques to manage and improve maintenance effectiveness and efficiency. This paper will be useful to researchers, maintenance professionals and others concerned with maintenance management.

Ubiquitous computing for dynamic condition-based maintenance : Table of Contents

Aitor Arnaiz Irigaray, Eduardo Gilabert, Erkki Jantunen, Adam Adgar — Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – The purpose of this paper is to describe a flexible architecture concept to provide a ubiquitous computing framework where condition-based maintenance (CBM) data and information can be easily accessed, and maintenance decisions may be performed wherever required. Design/methodology/approach – The architecture is based on a platform of intelligent web services, and logically structured decision layers based on the open systems architecture for CBM definition, from condition monitoring to decision support, and provides automated extraction of results. The application of web services is demonstrated, first related with an original vision on the adoption of mobile devices for dynamic maintenance management solutions, and then with a more conventional web-based predictive maintenance management system. Findings – Scenarios for the upgrade of existing preventive maintenance practices towards condition-based strategies are sufficiently different to require customised solutions. A web-based platform can work with such differences in a cost-effective way. Research limitations/implications – Further research can expand the actual platform by embedding new complementary web services. Practical implications – Condition-based strategies can provide clear savings in many maintenance activities. The platform described will provide the necessary flexibility to industrial users to manage the volume of data and information needed in CBM. Originality/value – The platform is flexible enough to provide intelligent processing “on-demand” and ubiquitously, with a three-level configuration of web services, agents and interfaces that facilitates interoperability with existing legacy systems. Finally, the platform can grow according to the needs of the user (e.g. new information, increased knowledge on the process, new measurements, etc.).

Development of ICT-based maintenance support services : Table of Contents

Ramin Karim, Peter Söderholm, Olov Candell — Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – The purpose of this paper is to describe a taxonomy for an eMaintenance management framework (eMMF) based on a service-oriented approach, in order to facilitate the development of information and communication technology (ICT)-based maintenance support services aimed at actors within the maintenance process related to complex technical industrial systems. Design/methodology/approach – To fulfil this purpose, a case study of a modern multi-role combat aircraft is selected as an appropriate research strategy and supported by a literature study. Empirical data are collected through interviews, workshops, document studies, and observations. A framework is developed and evaluated using a prototype within the studied case. The study is performed in close cooperation with the aircraft's type certificate holder and the customer representative and operator in one country. Findings – The proposed eMMF aids in the identification and development of ICT-based maintenance support services tailored for specific maintenance actors and their activities. Research limitations/implications – To further test the usefulness of the proposed framework, a larger scale application must be performed. This can involve additional stakeholders or a larger part of the technical system in the selected case, or another case dealing with complex technical industrial systems. Practical implications – The proposed framework supports the identification of required information services that support the maintenance process, which in turn supports the development of a service-oriented architecture (SOA) aimed at proper maintenance information logistics. Hence, people working with information logistics for maintenance purposes can use the framework as a support tool. Originality/value – The proposed framework combines a process and service-oriented approach, which facilitates the development of SOA-based information services by giving valuable input to more traditional system-oriented approaches.

Application of intelligent technique to identify hidden abnormalities in a system: A case study from oil export pumps from an offshore oil production facility : Table of Contents

Jawad Raza, Jayantha P. Liyanage — Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – The purpose of this paper is to illustrate the application of neural network approach to analyze machine's behaviour quantitatively. Design/methodology/approach – The model is developed based on real plant-data from a variable speed drive centrifugal type pump. The best model settings are recorded and tested for another similar unit in the vicinity to check its generalization capabilities. Owing to the absence of faulty data, this model is tested against preventive maintenance data that show symptoms of abnormality that are seemingly undetected in existing monitoring and control systems. The paper systematically summarizes published literature and suggests suitable network architecture and its capabilities by illustrative example from oil export pumps from an oil and gas offshore production facility. Findings – Artificial intelligent techniques provide a robust platform in providing useful information about system health and sub-optimal performance. Practical implications – In any industry, unexpected equipment downtime in principal questions the overall technical integrity of the platform raising major economical concerns. In the Oil & Gas sector, production platforms are in a 24/7 run mode, and thus undergoing major re-engineering processes by improving existing surveillance and control techniques of their asset. Machine degradation and abnormalities gradually affect performance and in some cases these are not visible in existing condition monitoring (CM) schemes. Recently, there has been an increasing demand for testing and implementing intelligent techniques as a subsidiary to existing CM programs to monitor and assess system's health. Artificial neural networks have emerged as one of the most promising technique in this regard. Originality/value – The proposed methodology highlights how healthy data from a system can be effectively modelled to identify significant abnormalities. This paper will be useful for experts working in the area of maintenance engineering to early identify state of the system performance.

Agent-based monitoring using case-based reasoning for experience reuse and improved quality : Table of Contents

Erik Olsson, Peter Funk — Sun Jun 07 14:15:03 BST 2009

Abstract:
Purpose – The purpose of this paper is to propose an agent-based condition monitoring system for use in industrial applications. An intelligent maintenance agent is described that is able to autonomously perform necessary actions and/or aid a human in the decision-making process. An example is presented as a case-study from manufacturing of industrial robots. Design/methodology/approach – The paper is mainly based on a case-study performed at a large multi-national company aiming to explore the usefulness of case-based experience reuse in production. Findings – This paper presents a concept of case-based experience reuse in production. A maintenance agent using a case-based reasoning (CBR) approach to collect, preserve and reuse available experience in the form of sound recordings exemplifies this concept. Sound from normal and faulty robot gearboxes are recorded during the production end test and stored in a case library together with their diagnosis results. Given an unclassified sound signal, relevant cases are retrieved to aid a human in the decision-making process. The maintenance agent demonstrated good performance by making right judgments in 91 per cent of all the tests, which is better than an inexperienced technician. Practical implications – Experienced staffs acquire their experience during many years of practice and sometimes also through expensive mistakes. The acquired experience is difficult to preserve and transfer and it often gets lost if the corresponding personnel leave their job due to retirements, etc. The proposed CBR approach to collect, preserve and reuse the available experience enables a large potential for time and cost savings, predictability and reduced risk in the daily work. The paper exemplifies experience reuse for quality improvement in production using a number of methods and techniques from artificial intelligence. Originality/value – The main focus of this paper is to show how to perform efficient experience reuse in modern production industry to improve quality of products. Two approaches are used: a case-study describing an example of experience reuse in production using a fault diagnosis system recognizing and diagnosing audible faults on industrial robots and an efficient approach on how to package such a system using the agent paradigm and agent architecture.