1. A method of transforming a G-code into a STEP-NC part program to convert a G-code type part program into a STEP-NC language type part program, the method comprising the steps of: receiving the G-code part program needed for creating the STEP-NC part program, tool information, and information on a numerical controller capable of analyzing a corresponding G-code; analyzing the received G-code part program according to the type of the numerical controller, and creating G-code block information; detecting a featured block by using the G-code block information, grouping G-code blocks along a boundary of the featured block, and partitioning the entire part program on a workingstep basis so that the entire part program is categorized into a setup workingstep and a plurality of machining workingsteps; creating tool information, machine function information, and machining technology information for each of the machining workingsteps by using the G-code block information corresponding to the machining workingstep, and creating internal information of the machining workingsteps by using the created information, the internal information including a means for creating machining operation information for categorizing machining operations into rough cutting and finish cutting, a means for creating manufacturing feature information of a corresponding machining workingstep by removing a region to be cut from a material region through a Boolean operation, and a means for creating machining strategy information including an approach strategy, a retract strategy, and a machining strategy of a tool; and if all the internal information of each of the machining workingsteps is created, arranging the machining workingsteps in the same sequence as that of machining operations executed in the G-code part program so as to create the STEP-NC part program.
7. A computer readable storage medium with a program for executing the method of transforming a G-code into a STEP-NC part program according to claims 1 to 6 stored therein.