Developpement d'un nouveau modele de planification de la production en aeronautique

This project studies some production planning problems encountered by companies that integrate production of experimental and standard parts while trying to optimise their manufacturing cells in order to reach the best efficiency. This is especially the case of aeronautic industry, the topic of this study.; In order to generate viable solutions, this dissertation presents one of the first studies about the viability of using an aggregated model to plan the production of different parts while levelling the load in order not to exceed available capacity. Our hypothesis is that this model will facilitate production while optimizing the use of resources, thus eliminating the occurrence of delay which can result in non-meeting of delivery dates.; To test this hypothesis, we will assume that raw material is always available on time and in sufficient quantity to fulfill demand. Moreover, the purchase of new equipment will not be considered since we want to study the possibility of optimising currently available resources.; To explore this aggregated model, one aeronautic company in particular has been analysed.; Current literature review pretty well the pros and cons of push and pull production systems. This literature review made it possible to establish that pull systems are more robust than push systems because it is easier to control work in process (WIP) and measure throughput than measuring WIP and controlling throughput. Pull systems allow a better control of inventories. Nevertheless, in this case study, it is impossible to consider a pure pull system using kanban or Constant Work In Process (CONWIP) to manage all production requests. Indeed, the low volume of production generated by the aeronautic industry must support a high production mix resulting in great variations in lead times while having to support very high demand for some parts and very low for others. Even if we exclude experimental parts which are, by their nature, incompatible with a production by kanban or CONWIP, the use of one of those methods for all standard parts is rejected because it would generate high process inventories, incompatible with high value added parts suitable to aeronautics.; To overcome this incompatibility while benefiting from the advantages of pull systems, we developed a new pull technique which is to be integrated into a hybrid push/pull system dealing with all demands. The proposed pull system is based on CONWIP, but does not use any intermediate inventory between work centers and is dedicated to parts with high production output.; The developed hybrid model, integrates a graphical wheel representation to illustrate the sequence of production of parts on the shop floor. The quantities of parts to be produced during a production run are established just before the start. To represent the capacity, the wheel is limited by a maximum number of parts (all parts together) to be put in production during a given period. The experimental parts are systematically issued according to capacity reservation made in advance by R&D engineers whereas the parts with low volume are planned according to the demand in order not to generate inventory. Once the quantities of experimental and low volume parts are assigned, the number of high volume parts to be manufactured is determined in order not to exceed the maximum number of parts allowed. Thereafter, the quantities of each part produced in high volume are decided using a new CONWIP-part system in order to maximize the ratio of the number of part X in WIP on the maximum number of part X allowed in WIP. Since parts are considered WIP as long as they are not consumed by demand, their production is indirectly controlled by demand and makes it possible to control inventories levels while levelling the load on manufacturing cells. Moreover, this method makes it possible to provide extreme flexibility for manufacturing experimental parts since last minute changes between experimental parts and high volume...