Using Geostatistics to Estimate the Variability of Autocorrelated Processes

Statistical quality control is used to detect changes in the parameters values of the process which usually are estimated under the assumption of independence of the sampling units with respect to the quality characteristic. However, this is questionable for many processes. The main objective of this paper is to present estimators for the variance of autocorrelated processes by using Geostatistics methodology. With this new procedure the usual Shewhart’s control charts still can be used to monitor the quality of the process. A Monte Carlo simulation study showed that the proposed estimators have good performance.