the Poisson distribution may not be the best model for describing the distribution of defects over the fixed length of matting. The assumption of a Poisson distribution is that events occur independently at a constant average rate. However, in this case, the machine’s reliability decreases as it gets closer to the time for servicing. This violates the assumption of a constant average rate, as the occurrence of defects may be affected by the machine’s deteriorating performance. Therefore, a Poisson distribution may not accurately capture the changing reliability of the machine and the distribution of defects in this scenario.