An access authorization for a computer-based object in an automation system comprising a plurality of network nodes is granted using a control file which is structured in line with a scheme for a markup language for granting access authorizations and which maps a hierarchic tree structure. In this case, access authorizations are mapped in an object model which has a hierarchic tree structure. A relevant subtree from the object model is ascertained for a selected network node, at which services are provided using computer-based objects, or when access to a computer-based object is requested, by an access guideline service. The control file is produced from the ascertained relevant subtree. The control file produced is made available for the selected network node or for access to the computer-based object.