U.S. Army Materiel Systems Analysis Activity Aberdeen Proving Ground United States
In the 1950s, ballistic vulnerabilitylethality VL emerged from the study of terminal ballistics as a focus on target end state. By the early 1960s, wargames evolved in which key inputs, generated by the VL community, were Probabilities of Kill PK. LossExchange Ratios LERs became a central measure of mission effectiveness. VL and wargames are but two of many fields developed largely independently in what might be characterized as a bottom-up evolution.