EN - PCCIN - Linha de Investigação de Gestão da Manutenção
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- Ships on Condition Data Driven Maintenance ManagementPublication . Lampreia, Suzana Paula Gomes Fernando da Silva; Lobo, Victor J. A. S.; Requeijo, José Gomes; Vairinhos, Valter MartinsOn condition maintenance management is gaining general acceptance both in ships as in other domains. This is a natural result given evolution of low cost sensors, statistical methodology, telecommunications, software and superabundance of observational data. In this paper we analyze the effects of digital revolution on the usual maintenance policies and anticipate its consequences on ships maintenance management. Specifically, we try to show that on condition maintenance is, intrinsically, a data driven maintenance policy and the natural solution that results from the convergence of those economic and technological realities. The existence of low cost, high quality sensors, means that sensor networks can be and are being installed in new and existing machinery projects. this means that high quality monitoring data is or can be continuously generated (thousand variables), at acceptble costs, covering all aspects considered relevant from the point of view of risks (consequences of failures), costs, nature and operational importance of equipment. This means the generation, transmission and in decisions and policies. the development of statistical methodology capable of transforming, in real time, those data mountains in useful knowledge is, nowadays, accomplished routinely using almost free software or, at least, easily accessible resources. The real problems are, frequently, realted with human resources and knowledge management, The paper identifies with real data examples some of the main consequences and issues associated to this new reality and its effects on main maintenance policies and mangement organizations.
- Diesel Engine Condition Monitoring Due to Different Operation AreasPublication . Lampreia, Suzana Paula Gomes Fernando da Silva; Lobo, Victor J. A. S.; Requeijo, José GomesWhen a ship design is developed, its engines are installed accordingly the owner requisites and the environment conditions in the designated operation area. Usually they are not adapted to sail all over the world. This implies that in some cases the power output cannot be the same for the safety of the engine, If a engine was conceived to operate on 16ºC of ocean sea, when it navigates on a 36ºC ocean, the engine power must be limited in order to not provoke major damage. Due to the fact, in this study two diesel engines will be monitor with online data collection and statistical treatment. The statistic treatment will be with the univariate control charts. With the engines operating on a range of ocean temperatures form 16ºC to 36ºC, the power limitatiom and the systems must be flexible due the use of the engines and consequently the use of ships over sea.
- Mapping the intellectual capital of cities and regionsPublication . Vairinhos, Valter MartinsContemporary cities or regions have complex challenges that require ongoing monitoring enabling intelligent answers in an appropriate period of time. There are many studies that indicate that this monitoring should take into account not only the tangible assets, but also the assets of intellectual capital. Several authors consider that these are the assets that are crucial either in sustainable innovation processes either in the process of developing the necessary reputation for building strong brands, able to attract talented people and investments. Based on the literature review and preliminary studies that compare the metrics for evaluating the intellectual capital of companies with the intellectual capital of the countries, this paper presents a theoretical model supporting the auditing and the mapping of intellectual capital management of cities and regions. This process is based on the creation of sensors for monitoring the intellectual capital and on the evaluation of how these are managed so as to support the decision making of the decision-makers and economic policy-makers. With this paper we intend to broaden the discussion on the importance of the decision makers of the strategies of cities or regions to support their choices on criteria that take into account the assets of intellectual capital.
- Comparative Analysis on Country Reputation through Patterns of Intellectual Capital: The case Portugal Versus Romania.Publication . Vairinhos, Valter MartinsIn the last decade the world economy has undergone numerous transformations that have changed the way we evaluate the assets of organizations, cities and countries. In this context, Intellectual Capital (IC) and Knowledge Management (KM), based on the management of intangible assets, became a factor of differentiation and competitiveness. The way countries are dealing with IC and knowledge management is a decisive factor in their international reputation, which in turn acts as country branding. Country branding is the image of a nation-state and from the link between this image and the success of its economy, corresponding to its competitiveness, its richness, the efficiency of the state and the quality of life of its citizens, among others. Reputable countries usually attract more investment and, consequently, are more innovative. While some decision makers argue that economic development should focus on investment and the creation of jobs, many studies have shown that this growth should be underpinned by the proper management of IC in all its dimensions. Assuming that is proved a cause-effect relationship between IC management and innovation - the most innovative countries are those with a better IC management and vice versa - the purpose of this study is to search for empirical evidence of a possible relationship between these indicators and the reputation of the countries. If it is possible to identify a connection between the variables that compose each index, we can design patterns that can guide the management of international branding strategy of each country. This paper uses multivariate data analyses techniques, including biplots methodology, in its attempt to study the case of Portugal versus Romania. These countries have different indicators, but both have problems in reputation management. In terms of originality, this empirical study aims to create discussions about the factors that determine the reputation of these countries.
- Leveraging intellectual capital through Lewin’s force field analysis (the case of software development companies)Publication . Vairinhos, Valter MartinsThis article outlines an original conceptual framework for the strategic management of intellectual capital assets in software development companies, interconnected with force field analysis approach. The framework allows assessing the opinions of the managers from software companies about the impact of both driving and restraining forces on the pillars of intellectual capital. Considering the capacity to adapt to change as one of the most relevant for the companies from knowledge intensive industries, this research uses a sample of 74 software development companies located in Romania to offer valuable insights on foresight capabilities to enable change benefits by managing the driving forces, respectively the restraining forces, at the level of IC pillars (human, structural and relational). The findings, represented by the average scores per each item embedded in the conceptual framework, show that the driving forces’ effects, quantified by means of PathMaker software’s Force Field Tool, are more significant than the restraining forces to change, in the case of each IC pillar. This paper’s original contribution consists of the explanatory power of the proposed framework to managers’ needs to find answers in the scientific research community to their challenging responsibility to drive change in their organizations through effective IC management. Furthermore, the article describes how the validation of the results encourages the implementation of change that aim to create value for the software development companies.
- Implementation of MEWMA Control Chart in Equipment Condition MonitoringPublication . Lampreia, Suzana Paula Gomes Fernando da Silva; Vairinhos, Valter Martins; Requeijo, José Gomes; Dias, J. M.The progressive degradation of presently operating electro-mechanical systems is a certain future fact. To minimize losses, maintenance costs and eventual replacements, condition monitoring should be applied to critical equipment (Condition Based Maintenance – CBM). The state of equipment can be predicted at any moment using statistical methods to analyze condition monitoring data. In this paper, collected data are vibration values, obtained at p points (p = 4 for instance) of an experimental equipment, forming p variables. When independence condition does not hold, it is suggested modeling data with Auto-Regressive Integrated Moving Average (ARIMA) models, and using the residues of the estimated model for Phase I. In Phase I, the estimation of parameters is achieved using the Hotelling T control chart; only after applying the defined ARIMA model, the p variables are treated. In Phase II, equipment state is artificially degraded through induced failures and failure prediction obtained using special multivariate control charts for data statistical treatment. Assuming data independence and normality, Multivariate Exponentially Weighted Moving Average Modified (MEWMAM) control charts are applied in Phase II to data collected from an electric pump, controlling the behavior of data using this procedure. In Phase II, for non-independent data the prediction errors from the adjusted model are used instead of original data. To show that the suggested methodology can be applied to propulsion systems, simulated data from a gas turbine are used. Using these methodologies it is possible to run online condition monitoring, and act in time, to minimize maintenance costs and maximize equipment performance.
- Opportunistic Maintenance Based on CUSUM Control ChartsPublication . Lampreia, Suzana Paula Gomes Fernando da Silva; Vairinhos, Valter Martins; Lobo, Victor J. A. S.; Parreira, Rui; Requeijo, José GomesThe use of a Ship Maintenance Management System is fundamental for the good performance of equipments and the entire platform. Over the systematic maintenance, the opportunistic maintenance is a concept that aims to minimize outages and costs preventing undesirable failures. To implement this kind of maintenance statistical methodologies must be used. The Cumulative Sum charts have a very good performance applied to processes control in quality control. We proposed the use of Modified Cumulative Sum control charts to equipment maintenance.The data under study are observations of cooling water and oil temperatures from a diesel generator. In the first phase, we will apply traditional control charts, and, in the second phase, the Cumulative charts with a certain Average Run Length will be used. Then we will compare the results and extract conclusions, presenting measures for improvement.
- Control Charts Limits Flexibility Based on the Equipment ConditionsPublication . Lampreia, Suzana Paula Gomes Fernando da Silva; Vairinhos, Valter Martins; Lobo, Victor J. A. S.; Parreira, Rui; Requeijo, José GomesCondition Based Maintenance became an important development in industrial and transport equipment maintenance efforts. Many statistical methodologies have been applied in this area. These methodologies are usually applied off-line: after the data is collected. We propose an online, real-time condition monitoring system based on a modified control chart, applied to engine parameters. These charts should be flexible enough and its control limits should reflect the equipment state, the manufacturer specifications and onboard meteorological conditions. In this study we will develop a methodology to specify flexible chart control limits. The experimental equipment is a combined diesel or gas propulsion system. Two phases will be assumed. In phase 1 the equipment and historical data are analyzed, studying historical data, which leads to the definition of equipment parameters. In phase 2, new data is obtained by simulation, and the Exponentially Weighted Moving Average charts are applied considering flexible limits.