Since the first activities concerning the monitoring networks of the Netherlands in 1986 a lot of optimalisation and adaptation steps have been made. A good maintenance regime, both for computer systems, software and for measuring stations is the key solution to trust in the early warning function of the network. Starting in 1986 the Nuclear Reserach and Consultancy Group (NRG) has built up a large expertise in the construction and maintenance of such early warning systems. This is also the benefit of having calibration facilities available on the company area of NRG for the different types of detection systems: calibrations can be performed for systems for gamma radiation, aerosols, iodine and the noble gases. Finally, with the Incident application, NRG can provide for the organisations involved in emergency planning and response a robust, user-friendly PC-application. With this application not only data can be extracted from a local computer system, at this moment tests are done with getting data from an external FTP-server.