Rehm, G. JACoW Publishing Geneva, Switzerland Apart from short term BPM resolution (repeatability), which aims at a few nm / sqrt(Hz) in modern systems, medium to long-term drift over durations of seconds to weeks (reproducibility) represents one of the challenges for BPM electronic developments. A number of approaches and compensation schemes have been developed and tested during the past years (e.g. cross-bar switching, pilot tone compensation, active temperature stabilization etc.) and experience has been gathered with environmental effects on electronics, cables and connectors. This talk will provide a review of drift effects and mitigation schemes for the next generation BPM systems.