The SME 3S Consult has over 25 years of experience in the development of mathematical models for thermo-hydraulic simulation of pressurized pipe networks such as water, gas and district heating systems as well as oil and gas pipelines. The main business of 3S consists in the combination of the development and sales of the proprietary hydraulic simulation software SIR 3S® and hydraulic engineering consultancies. In recent years the development of online simulation and monitoring techniques and implementation of online models (integrated or linked with SCADA) for clients from water supply, gas supply and district heating networks as well as for owner of oil pipelines have been key activities of the company. 3S has been involved in a number of national and international multi-partner research projects in the field of mathematical modelling of water supply networks and hydraulic engineering research (e.g. in SMaRT-OnlineWDN; SAFEWATER (FP7 – EU)). In the ResiWater project 3S will focus on development of robust hydraulic simulation models for supply systems under abnormal operating conditions (WP 4). The results will be combined within the framework of a training simulator for extreme operating conditions. The new software will be the basis for later integration within realtime-simulation frameworks (e.g. as part of the SCADA system of the utility) and offline software that is used for strategic planning and decision support by hydraulic engineers.