Optimisation de la planification intégrée de la maintenance préventive et de la production des systèmes multi-états

Cette thèse traite la problématique de la planification intégrée de la maintenance préventive et de la production des systèmes multi-états. Il s'agit d'un système de production modélisé comme étant un système multi-états avec un nombre fini de niveaux de capacité allant du fonctionnement parfait jusqu'à la défaillance totale. Il doit produire un ensemble de produits pour satisfaire une demande donnée durant l'horizon de planification. Les composantes du système multi-états sont assujetties à des remplacements préventifs et à une réparation minimale en cas de panne. Ce travail présente des modèles de planification permettant de générer simultanément le plan optimal de production au niveau tactique (problème de taille de lot capaci-taire) et les instants ou les intervalles d'intervention pour des actions de maintenance préventive. Les fonctions des objectifs de ces modèles minimisent la somme des coûts de la maintenance (préventive et corrective) et des coûts de production sujets à des contraintes de satisfaction de demande et de capacité. La méthodologie proposée développe des modèles mathématiques, des méthodes d'évaluation des temps de maintenance, des coûts de maintenance, les capacités relatives aux systèmes et des algorithmes de résolution pour obtenir des solutions optimales (recherche exhaustive) ou approximatives (algorithmes génétiques et recuit simulé). Cette méthodologie a été utilisée dans les trois contributions suivantes : 1. La première contribution propose un modèle de planification de la maintenance préventive périodique et de la production pour un système multi-états. Il s'agit de déterminer le plan de production optimal et les longueurs des intervalles de remplacement pour chaque composante du système. 2. La deuxième contribution traite du problème de la planification intégrée de la maintenance préventive acyclique et de la production dans le cas d'une seule machine. Le plan optimal détermine le plan de production et les instants d'intervention pour des activités de maintenance préventive. 3. La troisième contribution propose un modèle une planification simultanée de la maintenance préventive acyclique et de la production pour un système multi-états composé de plusieurs composantes. Les résultats obtenus dans cette thèse montrent l'impact économique réalisé par l'intégration de la planification de la maintenance préventive et de la production, ainsi que pour l'élimination de la contrainte de périodicité, surtout dans le cas d'une demande fluctuante. Les méthodes de résolution développées dans ces travaux permettent la résolution de problèmes de petite ou de grande taille

Integrating a cost-reduction shipment plan into a single-producer multi-retailer system with rework

This study integrates a cost-reduction shipment plan into a single-producer, multi-retailer system with rework process. In a recent article, Chiu et al. [1] have examined a single-producer, multi-retailer integrated inventory model with a rework process. For the purpose of reducing the inventory holding cost, this study combines an alternative n+1 product distribution policy into their model. Under the proposed shipment plan, an extra (initial) delivery of finished items takes place during the production uptime to meet the retailers’ product demands for the periods of the producer’s uptime and reworking time. Upon the completion of rework, multiple shipments will be delivered synchronously to m different retailers. The objectives are to find an optimal production-shipment policy that minimizes the expected system cost for such a supply chain system, and to demonstrate that the result of this study gives significant holding cost savings in comparison with Chiu et al.’s model [1]. With the help of mathematical modelling and Hessian matrix equations, the optimal operating policy for the proposed model is derived. Through a numerical example, we demonstrate our model gives significant savings in stock holding cost for both the producer and retailers

A study in joint maintenance scheduling and production planning

Master'sMASTER OF ENGINEERIN

The Effects of Variability in Demand and Time Parameters for Multi-Item, Multi-Echelon, Multi-Indenture Reparable Inventory Systems

The office of the Chief Information Officer is still new within public sector organizations. Further, the office of the CIO was hastily created by Federal laws that provide only broad direction for its implementation and practice while at the same time limiting each office\u27s power and reach within Federal agencies. Presently, because of broadly defined scope and the newness of the office in the public sector, Federal CIOs now face many challenges and critical technologies in managing their agency\u27s information resources. Private sector organizations have a valuable knowledge base from their CIO office implementation efforts and subsequent operations. This private sector knowledge could offer public sector CIOs invaluable insight into successful information resource management practices. However, public and private managers must take great care in deciphering which IRM prescriptions are relevant to their organizational situation. The goal of this research is to discover if public and private sector CIOs are faced with the same challenges and view the same technologies as critical for their organization\u27s operations .The results of an annual survey of public sector CIOs and senior IRM managers are compared with data collected from FORTUNE 1000 CIOs using the same instrument. Findings from this study provide evidence that public and private sector CIOs do perceive to be faced with many of the same challenges and also view many of the same technologies as critical to their organization\u27s operations

Whole life costing optimisation with integrated logistics support considerations.

It has long been recognised that, in the military sector, the Integrated Logistics Support ILS can significantly enhance system effectiveness and add value to their competitiveness. Hence, it is not surprising that many organisations outside to the military support the ILS adoption to increase their competence level. Even though the ILS underlying theory is general, there is a lack of suitable methodology that facilitates ILS implementation in other industries such as Oil & Gas industry. In particular when considering complex systems with long life-span, the optimisation of maintenance-related activities is important to fulfil system readiness, safety and whole life cost requirements. Modern petroleum equipment like gas turbines and drilling rigs are dependent on readily available maintenance supports in order to maximise their operational ability. Therefore, it has been identified that the study should be conducted to an effective use of ILS with the petroleum industry. In doing so, the usage of the ILS framework as a decision tool for maintenance optimisation is outlined. This framework embraces ILS concepts to support asset managers in developing their maintenance strategies. Level of repair analysis and spare parts management have been identified as potential areas for enhancing the use of ILS. In particular, maintenance optimisation is approached as a trade-off between investment in spare parts level and repair capacity. The developed framework delivers cost-effective support strategies obtained with iterative optimisation algorithm built on heuristics and genetic algorithm techniques. Finally, this algorithm has been implemented into computational algorithms. The framework can be employed to identify the optimum level of spare parts and the optimum amount of repair capacity for multi echelon repair network and multi-indenture systems. The framework has been used to carry out optimisations intended to maximise the availability of gas turbines by varying logistics support parameters. Typical results have shown that a joint optimisation of spare parts and level of repair analysis leads to better results than optimising them separately and emphasises the need for the developed framework. As part of this research, an expert panel validation method has been used to both refine the design of the developed framework and also evaluate its functionality from experienced practitioners within the Algerian petroleum industry. The results of this validation have demonstrated the advantages of integrating spare part management and level of repair analysis LORA to the problem of maintenance optimisation and shown that the framework is able to deliver optimal maintenance supportability decisions. The generic framework developed in this thesis can be seen a novel and comprehensive model for integrating two ILS elements into the operating tool in a manner that improves maintenance support provision, while remaining both flexible and usable; and therefore as a contribution to a better adoption of ILS technique within Algerian Petroleum Industry