Abstract:
The objective of this research is to study the approximation methods of Average Run Length (ARL) for Exponentially Weighted Moving Average (EWMA) control chart when observations are from Lognormal distribution by Markov Chain Approach (MCA). Furthermore, the MCA can be obtained an optimal parameter for designing of EWMA procedure when given the magnitude of changes of parameter δ = 0.01, 0.05, 0.10, 0.50, 1.00, 1.50 and 2.00 and fixed σ2 to be constant. The performance of control chart is characterized by the Average Run Length (ARL). The accuracy of numerical result obtained from MCA is compared with the results obtained from Monte Carlo Simulation (MC) which they are good agreement but the latter method takes computational times much more than the former.