PILOTE is a computer program that attempts to reproduce decisions of expert operators in scheduling outlet pumps at a water treatment plant. The program integrates both mathematical models and heuristics (i.e. rules-of-thumb used by operators to select configurations of outlet pumps). The models include statistical procedures for predicting hourly water consumption and a hydraulic simulation for estimating hour-by-hour elevation changes at regulating reservoirs and at the elevated reservoir receiving the pumped flows. The heuristics used by operators are based on factors related to water quantity and quality and operation and maintenance costs. An evaluation of the program showed that the statistical forecasting procedures performed well, but the simulation model consistently overestimated the volumes pumped. The heuristics included in the program accurately represented rules used by expert operators, except for rules used to rank order alternative pumping strategies. The evaluation provided an agenda of research for refining PILOTE so that it can be used routinely.