Hiroaki Sandoh, Nobuko Igaki and Toshio Nakagawa
The present study deals with an optimal inspection policy for a scale where the inspection for a scale is conducted when the elapsed time since the previous inspection or…
Abstract
The present study deals with an optimal inspection policy for a scale where the inspection for a scale is conducted when the elapsed time since the previous inspection or adjustment reaches T (> 0) for the purpose of detecting its uncalibrated or inaccurate state and where its uncalibrated state can also be detected empirically or accidentally. The design variable under such a policy is T (> 0). The expected cost per unit of time is formulated as an objective function to be minimized. The conditions under which an optimal inspection scheduled time T exists are then clarified. Numerical examples are presented to illustrate the theoretical underpinnings of the proposed formulation. The proposed model is also compared with the conventional one to show that the proposed model can reduce the cost.
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Hiroaki Sandoh and Nobuko Igaki
The present study proposes two types of periodical inspection policies for a scale which weighs products in the final stage of manufacturing some specific products, such as…
Abstract
The present study proposes two types of periodical inspection policies for a scale which weighs products in the final stage of manufacturing some specific products, such as chemical products. The scale is inspected at time iT(i=1,2, … ). Under ModelI, an inspection operation involves detection of a scale malfunction or inaccuracy as well as an adjustment activity. Under ModelII, an inspection is conducted only to detect a scale malfunction. If a scale malfunction is detected, an adjustment activity follows. For each model, the fraction defective and the long‐run average cost are formulated. We then examine the existence of an inspection interval Tα which makes the fraction defective under a prespecified value α (0< α <1). An economical inspection interval T* minimizing the long‐run average cost is also discussed.