This work introduces a comprehensive methodology for operation scheduling and campaign formation in the case of multipurpose batch plants. In phase and our of phase operation modes are taken into account. Intermediate storage is also considered and campaigns are built up yielding the precise amounts of intermediates to leave the storage tanks empty at their end. Furthermore, taking advantage of the IS, these campaigns may produce simultaneously products sharing equipment units. Campaigns are defined as a sequence of production runs of intermediates, from here on called mini-jobs, and thus scheduling may be carried out by means of simulation using units as soon as they come available. Once provided a friendly user interface, multipurpose schedules may be easily modified by hand, The proposed methodology will just require from the user the dispatching of a set of mini-jobs.