Optimal integrated maintenance/production policy for randomly failing systems with variable failure rate

International audienceThis article deals with the combined production and maintenance plans for a manufacturing system satisfying a random demand. We first establish an optimal production plan which minimises the average total inventory and production cost. Second, using this optimal production plan, and taking into account the deterioration of the machine according to its production rate, we derive an optimal maintenance schedule which minimises the maintenance cost. A numerical example illustrates the proposed approach, this analytical approach, based on a stochastic optimisation model and using the operational age concept, reveals the significant influence of the production rate on the deterioration of the manufacturing system and consequently on the integrated production/maintenance policy

Développement de stratégies de maintenance dans un contexte de sous-traitance partielle de production

Nowadays, the enterprises move under a hard competition. The satisfaction of the client in time becarne a difficult spot. Since that, the majority of the actual Company cal1 upon to the subcontractor in order to cover the client demand and to reduce the demand loss. In fact, it's time to expand new maintenance/production strategies by taking into account the context of subcontractor. In this memory we treat some maintenance policies integrated with production under the subcontractor constraint. The manufacturing system under consideration consists on machine Ml which produces a single product. In order to satisfy a constant demand d, the system called upon to subcontractor. The subcontractor is presented by another machine M2 which produces at a certain rate the sarne type of product as Ml. Both machines are subject to random failures. An age-limit policy is used for preventive maintenance of machine Ml. Point of view maintenance actions, the subcontractor is not controlled by us. We considered that the subcontractor imposes some unavailability periods. That's why we suppose that the failure rate of the subcontractor is constant. In this work we elaborated different strategies integrating maintenance and production. In these strategies we are taking in account the constraint of subcontractor. These strategies are optimised and its performances are compared to a simple maintenance policy SMP in which we don't taking in account the subcontractor. Finally, we classified al1 the strategies developed in this work according its performances orders compared to SMP and noted the performance constraints of theses policies.La modélisation impose de nos jours une remise à plat des politiques de gestion industrielle. Cette remise à plat est nécessaire pour la survie des entreprises évoluant dans un contexte de concurrence exacerbé et sans limite. Les politiques de maintenance des systèmes de production n'échappent pas à ce constat et leur remise en cause est nécessaire dans ce contexte. En effet, les politiques de maintenance traditionnelle ne permettent pas d'assurer la pérennité ainsi que la croissance durable pour les entreprises d'aujourd'hui, où la réduction des coûts et des délais est devenue l'objectif principal. Pour répondre a cet objectif, les entreprises font appel souvent à la sous-traitance qui est devenue la règle et non l'exception. Ceci impose une nouvelle contrainte dans la gestion de la maintenance. Dans ce cadre, le travail présenté dans cette thèse constitue une contribution à I'éIaboration d'une politique de maintenance faisant le couplage entre la gestion de la maintenance et la gestion de la production dans un contexte de sous-traitance. Le problème posé dans cette thèse traite des politiques de maintenance intégrant l'aspect production sous la contrainte de sous-traitance. Pour un système de production considéré, différentes politiques de maintenance intégrant l'aspect production ont été élaborées pour tenir compte de la contrainte de sous-traitance. Ces politiques ont été comparées par rapport a une politique de maintenance simple SMP ne tenant pas compte de la sous-traitance. Les conditions d'existences et d'unicités de l'optimalité de ces politiques ont été prouvées analytiquement et par simulation

Chapter 11 - Intelligent integrated maintenance policies for manufacturing systems

Artificial tntelligence techniques for networked manufacturing enterprises management, ISBN: 978-1-84996-118-9 (in press)International audienceNowadays, the fierce competition between enterprises has led many of them to revise their maintenance and production or service strategies. Satisfying customer demand in a timely fashion has become difficult due to the demand's random nature, a problem compounded by machine failures and low system availability. Much of the literature addressing this situation describes models and methods to optimize maintenance policies. By contrast, the research presented in this chapter is geared toward the development of a set of intelligent maintenance policies, which optimize integrated maintenance, inventory and production elements while satisfying random demand over future periods. This is a complex task due to the various uncertainties involved, which are due to external or internal factors. For instance, the variations in the environmental and operational conditions can be considered as external factors whereas the variations in the material availability can be considered as internal factors. The approach described in this chapter demonstrates the significant influence these factors have on the system failure rate, which is in turn important in the determination of an optimal intelligent maintenance strategy. We also emphasize that, on the one hand, high machine availability is an underlying assumption of just-in-time production control policies, and on the other hand, the traditional approach, which dissociates maintenance and production, is no longer satisfactory

Développement de stratégies de maintenance dans un contexte de sous-traitance partielle de production

La modélisation impose de nos jours une remise à plat des politiques de gestion industrielle. Cette remise à plat est nécessaire pour la survie des entreprises évoluant dans un contexte de concurrence exacerbé et sans limite. Les politiques de maintenance des systèmes de production n'échappent pas à ce constat et leur remise en cause est nécessaire dans ce contexte. En effet, les politiques de maintenance traditionnelle ne permettent pas d'assurer la pérennité ainsi que la croissance durable pour les entreprises d'aujourd'hui, où la réduction des coûts et des délais est devenue l'objectif principal. Pour répondre a cet objectif, les entreprises font appel souvent à la sous-traitance qui est devenue la règle et non l'exception. Ceci impose une nouvelle contrainte dans la gestion de la maintenance. Dans ce cadre, le travail présenté dans cette thèse constitue une contribution à I'éIaboration d'une politique de maintenance faisant le couplage entre la gestion de la maintenance et la gestion de la production dans un contexte de sous-traitance. Le problème posé dans cette thèse traite des politiques de maintenance intégrant l'aspect production sous la contrainte de sous-traitance. Pour un système de production considéré, différentes politiques de maintenance intégrant l'aspect production ont été élaborées pour tenir compte de la contrainte de sous-traitance. Ces politiques ont été comparées par rapport a une politique de maintenance simple SMP ne tenant pas compte de la sous-traitance. Les conditions d'existences et d'unicités de l'optimalité de ces politiques ont été prouvées analytiquement et par simulation..Nowadays, the enterprises move under a hard competition. The satisfaction of the client in time becarne a difficult spot. Since that, the majority of the actual Company cal1 upon to the subcontractor in order to cover the client demand and to reduce the demand loss. In fact, it's time to expand new maintenance/production strategies by taking into account the context of subcontractor. In this memory we treat some maintenance policies integrated with production under the subcontractor constraint. The manufacturing system under consideration consists on machine Ml which produces a single product. In order to satisfy a constant demand d, the system called upon to subcontractor. The subcontractor is presented by another machine M2 which produces at a certain rate the sarne type of product as Ml. Both machines are subject to random failures. An age-limit policy is used for preventive maintenance of machine Ml. Point of view maintenance actions, the subcontractor is not controlled by us. We considered that the subcontractor imposes some unavailability periods. That's why we suppose that the failure rate of the subcontractor is constant. In this work we elaborated different strategies integrating maintenance and production. In these strategies we are taking in account the constraint of subcontractor. These strategies are optimised and its performances are compared to a simple maintenance policy SMP in which we don't taking in account the subcontractor. Finally, we classified al1 the strategies developed in this work according its performances orders compared to SMP and noted the performance constraints of theses policies.METZ-SCD (574632105) / SudocSudocFranceF

Développement d'une politique de maintenance en se basant sur un plan de production optimal satisfaisant une demande stochastique, en prenant en compte le taux de service

International audienc

Integrated Maintenance Optimization with random demand and subcontracting constraint

International audienc

Optimal maintenance/production policy for a manufacturing system subjected to random failure and calling upon several subcontractors

International audienceIn this paper, we have developed an integrated maintenance policy for a manufacturing system subjected to a random failure and calling up on several subcontractor machines in order to satisfy a constant demand. In order to reduce the machine failure a preventive maintenance plan is made. The machine is unable to satisfy a constant demand, that's why it called upon another machine, comprising the so-called subcontractor machine, which produces at a certain rate the same type of product. In order to assure an economical objective, we have a choice between several subcontractors having some different data and to optimize the preventive maintenance plan. Two strategies are developed and optimized in this work. The first strategy, single subcontractor strategy, consists in choosing only one subcontractor among several ones. For this strategy we have proved analytically, that the choice of the subcontractor machines is conditioned by the unit lost cost due an unsatisfied demand of one product; The second strategy, switching strategy, consists in relaying on one subcontractor machine and then switching to another. An analytical study is developed in order to optimize firstly the preventive maintenance plan and secondly to determine the optimal switching date. A numerical example is developed for very strategy in order to apply the analytical results

An Optimal Production/Maintenance Planning Under Stochastic Random Demand, Service level and Failure rate

International audienceThis paper deals the combination between production and maintenance plan for a manufacturing system satisfying a random demand. A jointly optimization is made in order to establish an optimal production planning and scheduling maintenance strategy showing the machine degradation. The key of this study is to consider the influence of the production rate on the degradation degree. We prove simultaneously, with a constrained stochastic production-maintenance planning problem under hypotheses of inventory and failure rate variables, an optimal production plan and maintenance scheduling which minimizes the average total holding, production and maintenance costs. A numerical example is studied in order to apply the developed approach

Optimal integrated maintenance production strategy with variable production rate for random demand and subcontracting constraint

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TPM implantation in manufacturing systems: A survey of the state-of-the-art and extensions

Maintenance activities represent a significant pillar in industry. Its real goal consists at improving the production systems productivity. Specially, TPM represents one of the main evolutions of the maintenance methods in order to improve the machines efficiency by a proactive approach. This paper presents an overview of several TPM implantations and especially efficiency and effectiveness measurement of the TPM in several industries. In a second hand, a proposition of possible extension about analytical assessment of the TPM performance, based on both technical and economic criteria, is presented