Modelling of the dynamic behaviour of the reactive sputtering process is a key issue in many respects. Apart from increasing the basic understanding, such a model is also important for an active control of the process so that optimal deposition conditions can be maintained. This work is intended to present a basic model for the dynamic behaviour of the reactive sputtering process. The influence of the processing parameters on the transient behaviour is discussed. We found that the processing curves depend on the rate by which the processing parameters are varied. In particular, when measuring pressure-flow curves for increasing and decreasing reactive gas flow, the rate of change of the reactive gas supply strongly influences the width of the hysteresis region. (c) 2006 Elsevier B.V All rights reserved.