Comparison of production control systems to reduce work-in process inventory: An application in aviation industry

Within the scope of this thesis, the objective is to use the scarce of resources in production planning activities in the most efficient way, to monitor the production parameters obtained as a result of production planning and to analyze the effects of the deviations from the production amount. The study aims to examine the effect of hybrid production systems, which have been frequently studied in the literature in recent years, in real life production scenarios. By examining the constraints of the production systems, a mathematical model was constructed to maximize the production amount during the planning period. With the mathematical model, the outputs were analyzed for total work-in process inventory, the maximum and minimum production amounts of the stations, the maximum and minimum work-in-process amounts of the stations, monthly stocks, the ratio of the components produced, and the constraints that ensure production to be at least the shipment targets were also examined. To evaluate the performance of the underlying real system the outputs of three different scenarios were evaluated together through push, pull and hybrid production systems. Since full compliance with production plans is not always possible, a simulation model was designed to examine the effects of deviations from production quantities on compliance with customer targets. While designing the simulation model, the production amounts to meet customer targets were generated using different production deviation parameters. It has been evaluated that hybrid production systems can be used as an alternative for certain scenarios.