XbarM is a real-time analyser monitoring available on Sysmex 5-part differential analysers, XN-L Series and XN-Series, which uses patient samples measured during the daily lab routine. Unlike internal quality control with stabilised material, the XbarM offers a long-term and continuous control process over the entire working day. Using the XbarM, the functionality of all connected reagents, e.g. before and after reagent replacement is monitored in an optimal manner as well as the analyser itself, e.g. before and after calibration or sensitivity adjustment. It does not require any extra input from the user because, once activated and set up correctly, it runs automatically in the background. This SEED article describes the different types of monitored parameters, recommended XbarM settings as well as tips for troubleshooting.