Optimisation des politiques de surveillance par l'intégration du cadenassage/décadenassage dans la gestion de la capacité de production

Abstract

This work aims to develop an optimal strategy for production control in order to minimize production costs while taking into account occupational safety aspects through lockout / tagout during corrective and preventive maintenance activities. In the scientific literature, studies that address the integration of the lockout/tagout and production control are almost nonexistent. In addition, currently in industry, many managers and workers mistakenly believe that planning and carrying out the various lockout / tagout procedures takes a long time. Therefore, this idle production time is perceived as reducing the company's performance towards the planned production rate. To overcome this problem the innovative concept of "mean time to logout / tagout (MTTLT)" has been developed. The innovative concept of MTTLT is to be considered the lockout / tagout time according to the inventories levels for a manufacturing system to find an optimal policy. This concept allows on the one hand to reduce total production costs including inventory, shortage and maintenance costs over an infinite horizon and on the other hand to increase the safety worker level. This thesis is presented in three stages: In the first stage, the project aims to integrate the innovative concept of MTTLT into production capacity control. The MTTLT has been applied to a passive redundancy system (two machines, non-identical producing one type of part). A model has been presented using a homogeneous Markov chain, and the numerical solution of the Hamilton-Jacoby-Bellman (HJB) differential equations has provided the solution for our manufacturing system. Our results have been validated through a sensitivity analysis. In the second stage, MTTLT control has been applied to a production line consisting of three machines (two machines as passive redundancy and a third machine in series with the previous ones) producing one type of part. A model has been presented using an homogeneous Markov chain. The same tools used in the previous stage have also been used to solve this case. In this case, the simulation model has also been used to determine the costs associated with each combination obtained through the experimental design. Based on these costs, a regression analysis has been conducted to find the new optimal control of the optimization problem under consideration. To illustrate the usefulness of our results, a sensitivity analysis has been performed. In the third stage, this work focused on MTTLT and human error modeling for a FMS. Human error has been presented using a non-homogeneous Markov chain for a manufacturing system with passive redundancy producing one type of part. The solution has been obtained through the HJB equations and results have been confirmed by a sensitivity analysis.

Date	15 May 2012
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Sylvie Nadeau (Supervisor) & Jean-Pierre Kenné (Co-supervisor)