Search results for "Maintenance"
showing 10 items of 392 documents
Experienced knowledge for the description of maintenance packages
2015
International audience; The presented work is included in the research theme that specifies some means of capitalization andexploitation of knowledge from experience feedback processes in the context of industrial maintenancemanagement. Our research on it is a more precise definition of the proposed project, built with a problemasking how to handle the management of repair packages. Upstream, the knowledge of various expertsare materialized in the form of expert reports. Downstream maintenance wants to quickly repair productsbased on symptoms or change parts in advance. For this, we propose a methodology by analysing thefeedback to improve the response time for maintenance services. This is…
Assessing Software Replacement Success: An Industrial Case Study Applying Four Approaches
2006
This paper describes an industrial case study assessing software replacement success and other effects. The target of assessments has been a large commercial legacy system for customer register management. The success of its replacement by its performed rewrite has been assessed via four approaches concerning: user satisfaction, strengths and problems of the system, problem surveillance and expert judgments. The approaches and metrics have been selected in cooperation with industrial experts in order that they would meet the needs of their organization. The assessments have been conducted by comparing the situations before and after the rewrite. They have included quality aspects. The appli…
Smart Technologies in Software Life Cycle
2007
In software life cycle models traditionally the main attention is being paid to the software development, including requirement gathering (specification), design, implementation and testing. Less research is devoted to the system maintenance and operation despite the fact that these aspects take up the main part of the duration of a successful system. In the paper smart technologies are being analysed - architectural designs and software components which using meta information on system and its usage conditions are able to solve efficiently the problems of maintenance and usage: data quality and performance monitoring, software flexibility and testability, context dependant user interface. …
Software Modernization Decision Criteria: An Empirical Study
2005
Decisions regarding software evolution strategies such as modernizations are economically important. We present results of our empirical study of the views of decision makers. We have asked their views of the relative importance of 49 software modernization decision criteria. We have gathered data from Finnish software industry. There were 26 experts from 8 organizations involved. They were mainly upper or middle level managers. Our study shows that there is a large set of criteria which should be taken into account, and that those studied by us provide a good coverage of the relevant ones. We list the top-20 criteria. We also performed a cluster analysis which produced two groups of subjec…
Using semantics to facilitate data integration of offshore wind farms
2012
Operation and maintenance play an important role in extracting power from the wind, especially, in offshore wind energy where wind farms are located far off the shore and under harsh weather conditions. Improved operation and maintenance is likely to reduce costs as well as hazard exposure of the employees. Implementation of advanced information technology is thus crucial for operating offshore wind farms effectively and efficiently and hence improves operation and maintenance. However, information availability and reliability are key issues for their use in the offshore wind domain. In addition, the semantic of information has not been exploited thoroughly. This paper describes the develop…
Vibration signature analysis for rotor broken bar diagnosis in double cage induction motor drives
2013
The paper investigates the diagnosis of rotor broken bars in field oriented controlled (FOC) double cage induction motor drives, using current and vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of asymmetries in the machine are based on the signature analysis of electrical variables. The proposed diagnosis approach is based on optimized use of wavelet analysis by a pre-processing of phase current or axial/radial vibration signals. Thus, the time evolution of the tracked rotor fault components can be effectively analyzed. This paper shows also the relevance of the fault components computed from axial vibration sign…
Extended friction model of a hydraulic actuated system
2012
The main contribution of this paper is an experimental validation and comparison of three different friction models for an electro-hydraulic servo system. The first is the well-kn own LuGre model which incorporates dynamic friction effects. The second model is based on a relatively recent publication by Yanada in 2008 [6], which incorporates liquid film thickness in the servo valve. The third model is a new contribution presented in this paper, where valve underlap and mass acceleration are combined with the LuGre model. The experimental results show that for hydraulic systems, the film thickness model is an improvement over the LuGre model, while the new model presented in this paper is an…
Dynamics photovoltaic generators: Technical aspects and economical valuation
2010
The strategy adopted from many European nations and not, to entrust the electric energy production to differently energetic sources has determined an increment of the scientific research for the solar resource exploitation. These scientific community activities follows with attention from the entrepreneurial world have concentrated on the innovative techniques and methodologies of the source conversion, solar concentration and the direction's device optimization. This job focuses its attention on the simple application of solar-track device, based on consolidated technologies. The diffused application of these dispositive, could be, shortly, an important increment of electricity generation …
A predictive maintenance policy with imperfect monitoring
2010
For many systems,failure is a very dangerous or costly event. To reduce the occurrence of this event,it is necessary to implement a preventive maintenance policy to replace the critical elements before failure.Since elements do not often exhibit incipient faults, they are replaced before a complete exploiting of their useful life.To conjugate the objective of exploiting elements for almost all their useful life with the objective to avoid failure,condition based and,more recently,predictive maintenance policies have been proposed.This paper deals with this topic and proposes a procedure for the computation of the maintenance time that minimizes the global maintenance cost.By adopting a stoc…
Improving Maintenance Activities of Machine Tools
2013
The paper follows the current trends in the field of maintenance, proposing approaches that fit in the concept of Total Productive Maintenance (TPM). First it is presented a new proposal for tracking in-service machine tools. This is based on the identification of three operating states: good running condition, state of repair and stationary state. During the stationary state there are differentiated two distinct types of stops: natural stays and unproductive stays (those who often produce considerable losses). Based on the information contained in the records made for tracking the operation of machine tools there are proposed formulas for calculating some operational indicators and practic…