The invention involves a process and system for testing a technical system, such as an electronic control devices. The system includes a data processing system for executing a test sequence stored in memory. The data processing system communicates with the technical system via an interface. Data is transmitted by the executed test sequence to the technical system and/or read by the technical system. The test sequence for executing a test may be graphically displayed. The test sequence may be composed of executable program blocks in a graphical hierarchic arrangement, wherein a simultaneous execution of program blocks of the same hierarchal level can be determined by graphically arranging the program blocks adjacent to one another, and by executing program blocks of a different hierarchic level subsequently one after the other, by graphically arranging the latter among each other in the display.