Pursuant to a congressional request, GAO identified the extent to which the Navy's mainframe computer and peripheral procurements required compatibility with existing computer equipment or software.

GAO found that: (1) the Navy required compatibility with the largest manufacturer in 237 of its 411 compatible procurements, and compatibility with 3 other manufacturers in the other 174 procurements; (2) when the Navy required compatibility, it procured equipment from the largest manufacturer under 171 of those 237 compatible procurements; (3) the same manufacturer supplied the most equipment for the Navy's mainframe and peripheral procurements overall, including procurements that did not require compatibility; (4) in 1986, 1988, and 1989, the Navy obligated more dollars to that manufacturer's equipment and software than to any other manufacturer; and (5) the Navy obligated more dollars to another major manufacturer in 1987 because of one $52-million contract.