Figure 2.2:CONTROL HIERARCHY (IROFA)
The processing procedure of information from the design data to the machining was clarified as the first step of making to open. NC was classified into the processing hierarchy including the black box and the content which had to be processed by each hierarchy was defined. Its hierarchy was classified into seven layer in which each has input processing, operating and generating trajectory, main control part and so on.
Field which partially becomes possible by clarifying content of processing of each hierarchy development, and the participation of third party who is the expert in peculiar field was facilitated. In addition, each layer was made to the module and assumed to be a composition with which NC were able to be combined freely.
Next, the control hierarchy defined in seven layer is shown. This figure is the one having brought the result together with working group of the open NC committee of IROFA.