a tool for surveillance of animal wellfare in dairy cattle Animal welfare is a multidimensional concept, which is based on a good animal health and the species-specific behavior. Both are largely determined by management. These include the daily animal control and surveillance routinely available process data. Therefore, the research project aims to develop a monitoring tool that allows the farmer an effective control on the herd and individual level. The monitoring of animal welfare of individual animals or groups of animals is paramount based on the observed behavior. For the herd level analyzing whether directed changes are visible in key traits. For the individual animal level information on animal health, movement activity and behavioral parameters (e.g. lying behavior, feeding behavior) are important. The sensors used are commercially available products, the algorithms applied are Control Charts which allow merging of different sensors to an early warning system. The farmer is provided the monitoring system via the web-based 365FarmNet Farm Management Portal. The main task of the project is to use the information of marketable sensors to describe and evaluate the animal behaviour and put the results of the analysis on the web platform and mobile terminals as information to the farmer in ' Real Time' . The investigations are carried out on a practical dairy farm. The project provides four work packages : (1 ) establishment of the dairy farm , the installation of the sensor systems and integration of data in the different portals , ( 2 ) data acquisition (including documentation of animal health, animal behaviour), ( 3 ) optimisation of the algorithms for the early identification of conspicuous behavioural observations , setting up the web platform ( DairyNet , 365FarmNet ), ( 4 ) test runs of the implemented CowAlarm modules .