The Pinch Technology and the MIND method are combined in the analysis of a Swedish refinery. The heat exchanger network of the crude distillation system is analysed using the Pinch Technology. The results show that the steam demand from the boiler units in the energy supply part of the system can be reduced by 20% in the optimized heat exchanger network and by 21% when a heat pump is added to the system. A multi-period cost optimization of the operating strategy is performed using the MIND method. The results from the Pinch analysis are then input to the MIND optimization. The system cost of the total energy system of the refinery is optimized with regard to flexibility in the process system as well as changes of energy costs and the operating conditions of the cogeneration unit. The combination of methods shows that significant capital savings can be achieved when the energy saving potential of the process system is integrated in the overall operating strategy of the energy system. It is, in this case, possible to compare investments in energy saving measures to investments in increased steam production capacity.