Optimal allocation of intermediate storage tanks is an important issue in a batch plant to reduce its cost. In this work the design of multiproduct batch plant is analyzed; The proposed model considers simultaneously the possibility of having parallel units and intermediate storage tanks. The location of the storage tanks can be variable for each product. The problem is modeled as a MINLP (Mixed Integer Non Linear Program). This approach is compared to the one proposed by Ravemark (1995) where the intermediate storage tank location is the same for every product in the batch plant. Finally the results obtained in the execution of several examples are presented.