1. A method for installing or changing an executable computer program in an illumination system with a plurality of illumination devices controlled by a respective computer unit, wherein each of the illumination devices comprises a lighting device and a transmitting device arranged in or immediately at the lighting device, wherein the transmitting device wirelessly emits a signal with identification information specific to the transmitting device, the method comprising:providing data corresponding to the computer program to be installed or to be changed from a data source,
communicating the data to the illumination devices, and
installing the computer program in the respective computer units of the illumination devices in an automated manner or changing an already installed computer program in an automated manner based on the communicated data, wherein the installation of the change of the computer program is effected at a preset point of time;whereina communication link exists between the illumination devices,
a first one of the illumination devices obtains the data from the data source and for installing or changing the computer program in at least a second one of the illumination devices, the first one of the illumination devices communicates the data to the at least one second one of the illumination devices via the communication link.