The definition of the hydraulic network to be calculated is summarised under a model name in NetSim. This means that the pipes and nodes, production plants, pumps, etc. to be included in the network all have data in the model which has to be calculated. In NetSim, the description of nodes, pipes, etc. is divided between two types of data table , object data tables and model data tables. Names, coordinates, lengths are registered in the object tables. Connections between objects (pipe–node, pipe–pump, etc.), operating data, e.g. power, cooling, lifting height, pipe dimension are registered in model data tables.