Selecting and scheduling infrastructure rehabilitation projects

Targets for the condition and performance of water supply networks can be formulated from quantitative needs as well as from the demand for the quality and reliability of drinking water networks. To reach these objectives, a public or semi-public utility needs to invest in system maintenance and rehabilitation. For the system analyst it is difficult to give specific action threshold values for each indicator describing the network performance. Preferences differ and interdependencies between criteria do not allow, by conventional scoring models, determination of those projects which are the most efficient. Another method is presented for ranking rehabilitation projects according to multiple criteria with respect to efficiency. The development of the procedure and its implementation in software is part of a research project funded by Deutsche Forschungsgemeinschaft (DFG).