Search results for "Preventive maintenance"
showing 10 items of 10 documents
A simulated annealing-based approach for the joint optimization of production/inventory and preventive maintenance policies
2017
Even if more reliable than the past, the performance of modern manufacturing systems is still affected by machine’s deteriorations and breakdowns. As a consequence, adequate maintenance programs must be implemented to adequately satisfy demands during manufacturing stops due to unexpected failures or preventive maintenance (PM) actions. Despite production and maintenance are closely related issues, their joint optimization has become an important research topic just during the last decade. Therefore, the present paper proposes a model for the combined optimization of production/inventory control and PM policies with the aim of minimizing the total expected cost per unit time. The model is f…
Preventive maintenance versus cost of repairs in asset management: An efficiency analysis in wastewater treatment plants
2020
Abstract The operation and management of Wastewater Treatment Plants (WWTPs) is of paramount importance to guarantee the sustainability of water resources. Just like any other production process, wastewater treatment process involves different costs, such as: energy, personnel, maintenance and reagents. Regarding maintenance costs, they have become an issue of great concern to many operators in the last years. Maintaining the facilities in good condition ensures the proper performance of these infrastructures and reduces the risk of failures. It should be known that equipment breakdowns imply an increase in operating costs, with a high risk of generating an environmental damage due to the m…
Determination of Pareto frontier in multi-objective maintenance optimization
2011
Abstract The objective of a maintenance policy generally is the global maintenance cost minimization that involves not only the direct costs for both the maintenance actions and the spare parts, but also those ones due to the system stop for preventive maintenance and the downtime for failure. For some operating systems, the failure event can be dangerous so that they are asked to operate assuring a very high reliability level between two consecutive fixed stops. The present paper attempts to individuate the set of elements on which performing maintenance actions so that the system can assure the required reliability level until the next fixed stop for maintenance, minimizing both the globa…
Cost analysis of the facilities deterioration in wastewater treatment plants: A dynamic approach
2019
Abstract The implementation of the Directive 91/271 / CEE resulted in the proliferation of new Wastewater Treatment Plants (WWTPs) all around Europe. These facilities, which are compound by a wide range of assets (civil works, electromechanical equipment, pipelines, etc.), are ageing and deteriorating having an impact on the efficiency of the process. It is founded that repairs and corrective maintenance costs have increased in the last years, due to the deterioration process. Therefore, the aim of the present study is to focus on the cost effects of the deterioration process of the facilities in different wastewater treatment technologies. The analysis of these impacts will allow the opera…
Diagnosis of intermittent fault dynamics
2008
Diagnosis of intermittent faults is relevant for productive processes with a high level of maintenance caused by such failures. A characterization of diagnosed faults may save unnecessary repairs and enable better maintenance planning. This paper introduces the concept of diagnosis of intermittent fault dynamics. Moreover, a methodology for modelling intermittent faults and generating information for maintenance planning in discrete event systems is thoroughly covered.
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…
Applying Dynamic Performance Management to Public Sector Organizations
2016
This chapter will illustrate different examples of DPM applied to public sector organizations.
An exact algorithm for preventive maintenance planning of series-parallel systems
2009
Reliability is a meaningful parameter in assessing the performance of systems such as chemical processing facilities, power plant, aircrafts, ships, etc. In the literature, reliability optimization is widely considered during the system design phase and it is carried out by an opportune selection of both system components and redundancy. On the other hand, the problem of maintaining a required level of reliability by an opportune maintenance policy has been poorly examined. The paper tackles this problem for a system whose major components can be maintained only during a planned system downtime. An exact algorithm is proposed in order to single out the set of components that must be maintai…