1. A method of automated, computer-assisted plant occupancy planning in the process industry by means of an integrative relaxation approach for the sequencing of a discontinuous batch production and allocation of resources over time to a set of operations arising from batch planning, where during their execution the operations use resources, which may be available in multiples, and where productional restrictions are to be taken into account in carrying out the operations, where the problem of plant occupancy planning to be optimized is modeled as a resource-constrained project scheduling problem, taking into account the productional restrictions, where each operation corresponds to an activity of the project, for which it is possible to define an execution mode, a start time and an completion time, where restrictions on the availability of required resources and temporal constraints are to be taken into account, in a first step of the modeled problem, a relaxation which simplifies the resource problem is formed, disregarding the restrictions on the availability of resources, and taking into account the productional restrictions of the type of minimum and maximum time lags between operations and all the productional restrictions of the production break type which are independent of the selection of resources for operations, in a second step for the relaxed problem of plant occupancy planning, the temporal scheduling problem is solved as a calendarization problem in networks with the help of an iterative method, where in a third step, the solution to the temporal scheduling problem is investigated for its feasibility with respect to the non-relaxed problem of plant occupancy planning, where, when it is found that restrictions on the availability of resources are violated in the solution of the temporal scheduling problem, these violations are solved by introducing precedence relationships, and if it is found that not all resources have been selected for carrying out an operation, those resources are selected, the second step of temporal scheduling and the third step of introducing precedence relationships or selecting resources are continued until a feasible plant occupancy plan has been found or until the constraints to be taken into account in the second step of temporal scheduling are contradictory, if a possibility investigated does not violate any productional restrictions, the plant occupancy plan is stored as a feasible solution, investigation of possibilities according to the third step which have not yet been reviewed is continued, and a best solution with regard to a selectable objective function that does not decrease in the completion times of the operations is determined from the feasible solutions determined in the second step.