Method for performing tasks on a production computer system, comprising the steps of: - providing a configuration option for configuration of predetermined implementation parameters for a task of a production computer system by a key computer system, - creating at least one task description file in the key computer system using configured implementation parameters, wherein the task description file contains a description of a task on the production computer system, - automated transmission of the task description file from the key computer system to a task computer system and storing the task description file in the task computer system, - requesting the stored task description file in the task computer system - automated transmission of the task description file from the task computer system to the production computer system, - verifying, by the production computer system, the allocation of the task description file to at least one task stored on the production computer system, - executing, in the production computer system, the task allocated to the task description file using the task description file, if the verification of the allocation was successful, wherein the task computer system comprises open ports such that access of a user of a first user group to the task computer system is configured and wherein the production computer system keeps all ports essential for the method permanently closed in such a way that no programs for external addressability are running on these ports and thus access of a user of the first user group to the production computer system is prevented during the performance of the above steps in a predetermined operating state of the production computer system, wherein, however, upon instruction of the production computer system, a process for transmitting the task description file from the task computer system to the production computer system is started and transmitting of the task description file is initiated by the production computer system, wherein the production computer system controls the exchange process, and wherein the key computer system manages predetermined access rights and/or keys of users of a second user group and access of a user of the second user group to the key computer system is configured, however access of a user of the first user group to the key computer system is prevented, at least in a predetermined operating state of the key computer system. - providing a configuration option for configuration of predetermined implementation parameters for a task of a production computer system by a key computer system, - creating at least one task description file in the key computer system using configured implementation parameters, wherein the task description file contains a description of a task on the production computer system, - automated transmission of the task description file from the key computer system to a task computer system and storing the task description file in the task computer system, - requesting the stored task description file in the task computer system - automated transmission of the task description file from the task computer system to the production computer system, - verifying, by the production computer system, the allocation of the task description file to at least one task stored on the production computer system, - executing, in the production computer system, the task allocated to the task description file using the task description file, if the verification of the allocation was successful,