1. A system for determining an effectiveness of production installations of various types, significant fault events which bring about deviations from a prescribed desired effectiveness, and causes of the significant fault events, the system comprising: a data acquisition device to be connected to a respective production installation and set up for continuous acquisition and ready-to-call-up storage of data including installation-related data and production-related data; and a service device connected to said data acquisition device, said service device including: an input device for inputting additional descriptive data including installation-related descriptive data and production-related descriptive data that cannot be called up from said data acquisition device; a display device for displaying the effectiveness determined, the significant fault events and the causes of the significant fault events; an online system part connected to and set up for calling up the installation-related data and the production-related data from said data acquisition device, said online system part having a fault event detector detecting the significant fault events on a basis of the data, the additional descriptive data input by said input device, and on an overall equipment effectiveness (OEE) script, said online system part determining the significant fault events by fault event evaluation using a configured assessment model, determining in each case the causes of the significant fault events using a configured fault model, and calculating the effectiveness; an offline system part connected to said online system part, said offline system part one of containing and has access to a number of models including generic fault models and assessment models, said offline system part set up for searching for the models on a basis of at least one of called-up and input descriptive data, said offline system part configuring the models and storing the models one of locally and in a locally distributed form, said offline system part configured for storing the models in said online system part as one of the configured assessment model and the configured fault model.