Inspection policy for a scale considering accidental detections

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.