Method and engineering system for modifying a program of an industrial automation component

An engineering system for modifying a program of an industrial automation component, the program consisting of a plurality of program elements, comprising:

• a processor;
• and
• memory;
• wherein the engineering system is configured to modify the program by transferring modified program elements and program elements which are dependent thereon to the automation component;
• wherein at least part of the program is structured in units,
• wherein a unit comprises a group of program elements, a unit additionally being comprisable of both published program elements, each having an interface referenceable by the program elements of other units, and unpublished program elements, each having an interface referenceable only within the same unit;
• wherein the engineering system is further configured to utilize characteristics of interfaces of the published program elements of each unit to form a checksum and to associate said formed checksum with the unit in each case;
• wherein a modification to at least one program element of a version of a unit which is stored on the engineering system results in the checksum of the thus modified unit being compared with the checksum of the previous version of this unit which is present on the automation component;
• and
• wherein, in an event the checksums match, only the modified unit is transferred from the engineering system to the automation component, otherwise all other units which reference the modified unit are also transferred to the automation component in their respective current version of the engineering system.