Mounir Elleuch, Habib Ben Bacha, Faouzi Masmoudi and Aref Y. Maalej
The aim of this paper is to illustrate a solution that can be used to reduce the severity of breakdowns and improve performances in the cellular manufacturing (CM) system with…
Abstract
Purpose
The aim of this paper is to illustrate a solution that can be used to reduce the severity of breakdowns and improve performances in the cellular manufacturing (CM) system with unreliable machines.
Design/methodology/approach
The performance of CM system is conditioned by disruptive events, such as the failure of machines, which randomly occurs and penalizes the performance of the cells, seriously disturbing the smooth working of the factory. To overcome the problem caused by the breakdowns, the authors develop a solution, based on the principle of virtual cell and the notion of intercellular transfer that can improve the availability of the system. In this context, the use an analytical method based on Markov chains to model the availability of the cell. The results are validated using simulation.
Findings
The proposed solution in this paper confirmed that it is possible to reduce the severity of breakdowns in the CM system and improve the availability of the cells through an intercellular transfer created at the time of a breakdown. Simulation allowed a validation of the analytical model and showed the contribution of the suggested solution.
Originality/value
The developed approach studies the performance of the production cells formed by unreliable machines. It uses the notion of the intercellular transfer to improve the availability of the cells.
Details
Keywords
Imen Jaafar, Faouzi Ben Ammar and Mohammed Elleuch
This paper aims to integrate cascaded multilevel converters in the static compensator (STATCOM) systems in order to assure dynamic compensation of the reactive power absorbed by…
Abstract
Purpose
This paper aims to integrate cascaded multilevel converters in the static compensator (STATCOM) systems in order to assure dynamic compensation of the reactive power absorbed by fixed speed wind turbines.
Design/methodology/approach
The cascaded multilevel converter topology is incorporated as a variable source of reactive power required by the wind farm. The evaluation of reference reactive currents is assured by the technique of instantaneous power theory. Thus, the STATCOM, with its appropriate control strategy, continuously compensates the reactive currents.
Findings
A developed non‐linear state representation makes possible the analysis of static and dynamic behaviour of the proposed system. The STATCOM‐based cascaded multilevel converter is able to provide continuous compensation and proves highly dynamic under steady state and transient operating conditions.
Practical implications
The paper formulates a mathematical model which includes all parameters describing the system composed by a medium voltage network, a wind farm and a STATCOM‐based cascaded multilevel converter. The study may help to develop new control methods of such power systems containing non‐linearities and an extended number of parameters.
Originality/value
Since there are few studies on comprehensive and complete models of power systems, the paper contributes to make both a study and a simulation based on a developed non‐linear state model which perfectly describes the state and transient behaviour of the proposed system.
Details
Keywords
Hassana Mahfoud, El Barkany Abdellah and Ahmed El Biyaali
The purpose of this paper is to review maintenance strategies within the healthcare domain and to discuss practical needs as gaps between research and practice.
Abstract
Purpose
The purpose of this paper is to review maintenance strategies within the healthcare domain and to discuss practical needs as gaps between research and practice.
Design/methodology/approach
The paper systematically categorizes the published literature on clinical maintenance optimization and then synthesizes it methodically.
Findings
This study highlights the significant issues relevant to the application of dependability analysis in healthcare maintenance, including the quantitative and qualitative criteria taken into account, data collection techniques and applied approaches to find the solution. Within each category, the gaps and further research needs have been discussed with respect to both an academic and industrial perspective.
Practical implications
It is worth mentioning that medical devices are becoming more and more numerous, various and complex. Although, they are often affected by environmental disturbances, sharp technological development, stochastic and uncertain nature of operations and degradation and the integrity and interoperability of the supportability system, the associated practices related to asset management and maintenance in healthcare are still lacking. Therefore, the literature review of applied based research on maintenance subject is necessary to reveal the holistic issues and interrelationships of what has been published as categorized specific topics.
Originality/value
The paper presents a comprehensive review that will be useful to understand the maintenance problem and solution space within the healthcare context.