A dynamic inspection model for wearing production systems

The aim of this paper is to correlate the deterioration process of a production system with the items control process and, as a consequence, with the equipment inspection policy. The objective is to consider how the wear of the manufacturing system influences the values of the control process parameters and how these parameters have to be changed in accordance with the need to maintain optimal (working) conditions. Adopting a Weibull failure-time distribution, it is shown how these parameters must be changed (at different times t) in order to maintain optimal working conditions. To test the inspection model, a weighted cost function dependent on the time loss for the production of defective units and for the production shut-down (in order to make an inspection to control the state of the system) is developed.