This article proposes control charts to monitor an inspection process based on the defective proportion of the inspected parts. The focus is on inspection process where the incoming parts form a sequence of independent units, such as unrelated clients arriving at a service facility. An example of this kind of inspection process is the periodic motor vehicle (PMVI) inspection. The effectiveness of the proposed control is evaluated using Monte Carlo experiments and is applied to an actual PMVI station. Copyright © 2009 John Wiley & Sons, Ltd.