The present invention is a machine implemented, design automation method that assists a designer in the understanding of a software and/or hardware source code specification by transforming the source code into a simplified specification called a program slice. The present invention extends graph-based program slicing to the hardware-software interface that is commonly found in embedded systems. In addition to the known benefits of program slicing applied to a pure software or pure hardware, the present invention aids a designer in understanding the complex interaction between software procedures and hardware processing elements in the context of a codesign methodology.