Differently from continuous processes, the processing schedule of batch processes should be modified for heat exchange between batch streams. In most batch processes in which ZW policy is adopted, the heat integration causes the increased production cycle time that requires the bigger batch equipments sizes. Process design engineers usually finish the initial batch process design neglecting the possibilities of heat integration due to the increased equipment costs in that case. In this study, the schedule of multi-product processes, the required equipments sizes and the heat exchange between batch streams are mathematically formulated in a mixed integer nonlinear programming. A solution of this formulation can be readily obtained with a commercial MINLP solver. Numerical examples are presented to illustrate the possibilities of heat exchange in a multi-product batch process.