An Investigation of Statistical Quality Control Applications in a Job Lot Grinding Process

摘要

An investigation was made to study the effect on the variability of a process by changing the dimension of the characteristic which it produces, with the objective of using this knowledge of process variation to establish statistical quality control charts throughout the range of constant variation. The final grinding operations on the internal and external diameters of three different sizes of stator ring assemblies were studied. A study was made of the manufacturing environment and data were collected. Statistical quality control charts were constructed for each production lot sampled. The findings of the statistical tests and the results of the study of the manufacturing environment revealed that the variability of the two grinding processes studied can be held constant over a dimension range of 1.937 inches to 3.7290 inches if the factors of tolerance and measuring practices are held constant. Also, it was found that statistical quality control charts based on a prior knowledge of process variation can be used effectively in the environment of the study. (Author)