The effect of autocorrelation on control charts performance and process capability indices calculation

Chemical processes as well many non-industrial exhibit autocorrelation, for which the above-mentioned control procedures are not suitable. This paper considers problem of monitoring a process in observations can be represented first-order autoregressive model following heavy tailed distribution. It also presents practical usage time series charts on chemical concentrations. The second part discusses effect autocorrelation capability analysis when made by an first order. indices provide measure how fits within specification limits. When calculating indices, it is usual to assume that data independent. simulation study this higher order indices.