Method for determining the processing order of modules in a function plan for a sequentially operating automation system, - each module being assigned a module identifier (A, B, C,..., I) in a reversibly unambiguous manner, - the modules being linked, on the signal side, by means of inputs and outputs, and - in the case of a module having a plurality of outputs, these outputs respectively being organized in a predefined manner, and the signal path in the function plan being respectively traced in a recursive procedure in the forward direction starting from a starting module and being traced back in the reverse direction, - a predefined set of propagation rules respectively being used as a basis for propagation in the forward direction and propagation in the reverse direction, - the modules which are reached during forward propagation being assigned a sequence list whose list elements comprise the module identifiers (A, B, C,..., I), - the sequence list available after the previous pass being updated during each pass through the recursion loop using the current sequence list, and - the order of the list elements in the sequence list available after the method has been concluded being used as a representation of the processing order of the modules, - the function plan being segmented into partial plans, the order of the partial plans being taken into account when determining the plan-internal processing order of the modules, in that the sequence list is updated by inserting the sequence list obtained in the current pass through the recursion loop into the previous sequence list, the insertion being effected immediately after that list element which represents the starting point of the forward propagation carried out last, in that the propagation path pursued during the previous propagation operations in the forward direction is traced back during reverse propagation and in that reverse propagation is aborted as soon as the module reached in the current propagation step is the starting module or a module having an output connection which has not yet been traced during the previous recursion loops. - each module being assigned a module identifier (A, B, C,..., I) in a reversibly unambiguous manner, - the modules being linked, on the signal side, by means of inputs and outputs, and - in the case of a module having a plurality of outputs, these outputs respectively being organized in a predefined manner, - a predefined set of propagation rules respectively being used as a basis for propagation in the forward direction and propagation in the reverse direction, - the modules which are reached during forward propagation being assigned a sequence list whose list elements comprise the module identifiers (A, B, C,..., I), - the sequence list available after the previous pass being updated during each pass through the recursion loop using the current sequence list, and - the order of the list elements in the sequence list available after the method has been concluded being used as a representation of the processing order of the modules, - the function plan being segmented into partial plans, the order of the partial plans being taken into account when determining the plan-internal processing order of the modules,