USING THE STABLE DISTRIBUTION TO MONITOR A PROCESS, WHICH DISTRIBUTION IS UNKNOWN

The control chart is a tool of statistical quality control, which is widely used in production. The fulfillment of its basic assumptions, guarantees flawless assessment of correctness of the monitored process. The purpose of this paper is to pay attention to the need to verify the assumptions of the used method and the effects of its unauthorized use, in case of not meeting its assumptions. In this paper a method that uses a family of stable distributions to estimate the unknown probability density of monitored diagnostic variable, is proposed. The estimated density function is the basis for determining the control limits.