An optimal scheduling model for ready mixed concrete supply with overtime considerations

The incorporation of overtime considerations in the production and dispatching of ready mixed concrete (RMC) is a complex real world problem. In this research, the authors develop a network flow model for an RMC carrier according to Taiwan's operation situation, that integrates RMC production scheduling and truck dispatching in the same framework, to decide on an optimal RMC supply schedule which also integrates overtime considerations. To build the model, the authors employ a time–space network technique to formulate the production of RMC and the truck fleet flows in the dimensions of time and space. The model is formulated as a mixed integer network flow problem with side constraints. To efficiently solve the problem a solution algorithm incorporating a mathematical programming solver is developed. The network flow model and the solution method are then evaluated using real operating data. The test results show that the model and the solution algorithm could be useful for actual operations.