In this paper, an evaluation of a product replacement ratio of irreparable items to the normally working ones is performed with a view to a warranty analysis. It is demonstrated that the replacement ratio during the warranty period can be estimated from t

In this study, a reliability analysis method is discussed for the evaluation of the withdrawal ratio of non-repairable items to the normally working items of a controller product model. Although the analysis method is rather straightforward, one can estimate the probability of withdrawal and present the management a useful information on the appropriateness of the warranty period, exploiting the collected data, which is commonplace in the industrial site. For the methodology is to be refined, more systematic collection of data and adoption of more sophisticated analysis method are yet to be desired.