Methods for developing and validating survivability distributions

: Discusses methods that can be used to develop survivability distributions based upon three sources of knowledge. These are (1) available test results; (2) little or no available test data, but a good understanding of the physical laws and phenomena which can be applied by computer simulation; and (3) neither test data nor adequate knowledge of the physics are known, in which case, one must rely upon, and quantify, the judgement of experts. Describes the relationship between the confidence bounds that can be placed on survivability and the number of tests conducted. Discusses the procedure for developing system level survivability distributions from the distributions for lower levels of integration. Demonstrates application of the techniques by defining a communications network for a Hypothetical System Architecture. A logic model for the performance of this communications network is developed, as well as the survivability distributions for the nodes and links based on two alternate data sets, reflecting the effects of increased testing of all elements. Shows how this additional testing could be optimized by concentrating only on those elements contained in the low-order fault sets which the methodology identifies.