1. A computer program embodied on a computer-readable medium having a hierarchical software management structure, said computer program comprising: a first replaceable unit further comprising a first header and first body, said first header comprising first identification data, said first header further comprising a first list of hardware on which said first replaceable unit is dependent for proper operation; a second replaceable unit further comprising a second header and a second body, said second header comprising second identification data; said first body comprising said second identification data, thereby allowing said first replaceable unit to link to said second replaceable unit in a hierarchical fashion; said second body comprising operational code necessary to run said computer program; said first body contains no operational code necessary to run said computer program; and said first header further comprising a description of the function of said operational code.