Özet:

One of the main factors affecting the quality of the product in production systems is the quality of the manufacturing process that produces the product. Failure of production equipment can increase the rate of faulty products and reduce the production time due to the time spent in repair. In order to minimize the failures, the reliability of the machines should be modeled and the machine maintenance plan should be determined in line with the predictions obtained from the model. The aim of this study is to model the mechanical failures that may occur during fabric production in a circular knitting machine in a company in the bedding fabric sector in Turkey by using counting processes. In the study, firstly, the production and failure records of the past days were examined and the mechanical failures in production were determined and arranged. As a result of trend analyzes using graphical methods and hypothesis tests, it has been determined that the appropriate model for the failure behavior of the machine is the Nonhomogeneous Poisson Process (HOPS). The failure density function of HOPS is expressed by the Power Law model. The adequacy of the model was demonstrated by the goodness-of-fit test based on R2. Reliability measures estimated from the model revealed that the machine was failing more and more frequently. This showed the necessity of overhauling the machine in order to minimize production time loss and quality loss. This study example demonstrates the importance of reliability analysis in maintenance planning.

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