The Defense Nuclear Agency was an offspring of the Manhattan Project and is now part of the Defense Threat Reduction Agency. In its various guises it had many responsibilities connected with America’s nuclear weapons programmes.
In the 1980s and 1990s it produced a series of calculators to help the military plan its nuclear attacks on targets in the USSR and other countries. The US had a list of target Vulnerability Numbers [see this post]. Planners could use these numbers and the DNA calculators to decide whether a bomber, a submarine launched missile or a ground launched missile be used against a target [they had different levels of accuracy] to achieve a specified level of damage and probability of success.
This blog has posts on all these. The list is incomplete because the DNA produced a Damage Prediction Rule VN – 1 in 1982 [see this post].
As soon as a introduction of the IBM PC created a technical standard for personal computers the DNA began producing nuclear targeting software programs. Some of the DNA’ss programs duplicated the functionality of the above slides rules. The Multi-sigma Damage Prediction Rule was produced as both a physical slide rule and as software programs for hand held and desktop machines. Programs for a long list of other targeting functions were added to the DNA catalogue.