This paper considers the run by run control problem. We develop a framework to solve the problem in a robust fashion. The framework also encompasses the case where the system is subject to delayed measurements. Recent results available for the control of such systems are reviewed, and two simple examples are presented. The first example is based on the end-pointing problem for a deposition process, and is subject to noise which has both Gaussian and uniform components. The second one is concerned with rate control in a LPCVD reactor.