GRA 424 Final: GRA424-Exam-Notes

• School: Ryerson University
• Department: Graphic Communications
• Course: GRA 424
• Professor: Martin Habekost

Document Summary

Purpose: to determine the stability of counted data when the opportunity is large compared to the actual number of defects. I. e. injuries per month or falls per month: plots the number of defectives. Per machine: assumes the defects of the quality attribute are rare, assumes control limits are computed based on the poisson distribution (distribution of rare events, used to monitor count -type data. Typically total number of nonconformities per unit: accounts for the possibility of more than one nonconformity per inspection unit. Ucl = p + 3 p (1 - p ) n. Lcl = p - 3 p (1 - p ) n p = np n. 1)the number of opportunities or potential locations for nonconformities is very large. 2)the probability of nonconformity at any location is small and constant. 3)the inspection procedure is same for each sample and is carried out consistently from sample to sample.