In 2009, the survey of Wei and Craig reported qualitatively on the benefits of process control systems in grinding and flotation. The present review of about twenty milling operations reports quantitatively on these benefits. Expert systems, model predictive controller, and fuzzy logic control systems, to name only the most used in the mining industry, have delivered superior operational performance (1-16% gain in ore throughput, at least 40% reduction in mill load variability, up to 1% in metal recovery in flotation) and reduced operating costs (15% reduction in grinding media consumption 52% reduction of the cyclone pressure variability). (C) 2015 Elsevier Ltd. All rights reserved.