 This approach to integration facilitated a higher level of verification than would have been available using replacement of smaller components, providing for “...easy reconfiguration of the modules over their life span of 30 years.” It also permitted the architecture to accommodate the subsequent change in orbital inclination by moving some of the heavy racks off the initial launch of the module.The distinctive size and shape of the of both the common hatch and CBM enabled this concept of module integration because they permitted movement of the large racks into, and out of, the modules while on orbit.Other system-level decisions in this time frame also affected the eventual design of the CBM.