The Prediction of Cellphones’ Fault Rates with Grey Models

The prediction of the faulty rate of a cellphone is essential for the supply chain management system of spare parts. However, the fault rate of the mobile is affected by many factors that makes it difficult to predict. In this work, some new concepts for prediction of faulty rate based on grey model theory such as grey fault rate and grey model fault count are proposed. It is found that the grey fault rate is consistent with the bathtub curve that widely applied in the reliability engineering. The grey model theory is utilized to solve the problem of random individual fault affecting the prediction negatively. The characteristic value of the grey failure rate is defined to describe the fault rate for certain phones’ models. We develop the method to predict the fault of a new phone model based on the data of certain old phone models and their grey failure rate. The proposed method is applied to fault rate prediction of two cellphone models that results with the prediction deviation about 2% over 3 years.