This paper presents new alternatives in the retrofit model of multiproduct batch plants. Besides the duplication of the batch units implemented in previous works, the model considers the inclusion of intermediate storage tanks. These tanks can be plainly added or replace existing units that can be sold. The allocation of intermediate storage tanks is not considered in the previous retrofit works, even if this alternative is not new in the design of multiproduct batch plants. This option allows getting more efficient and real world solutions, although it requires working with a more complex model. (C) 2003 Elsevier Science Ltd. All rights reserved.