OPTIMAL ADJUSTMENT IN THE PRESENCE OF DETERMINISTIC PROCESS DRIFT ANDRANDOM ADJUSTMENT ERROR

A state-space process-control model involving adjustment error and det erministic drift of the process mean is presented. The optimal adjustm ent policy is developed by dynamic programming. This policy calls for a particular adjustment when a Kalman-filter estimator is outside a de adband defined by upper and lower action limits. The effects of adjust ment cost, adjustment variance, and drift rate on the optimal policy a re discussed. The optimal adjustment policy is computed for a real mac hining process, and a simulation study is presented that compares the optimal policy to two sensible suboptimal policies.