Tin whiskers present a significant reliability risk in military systems because of the potential for short circuits.
Tin whiskers are electrically conductive, crystalline structures of tin that sometimes grow from surfaces where tin, especially electroplated tin, is the final finish.
One of the difficulties with risk assessment of tin whiskers is the ability to quantify the risk. Attached are documents and presentations developed from work on the Strategic Environmental Research and Development Program (SERDP) Project WP1753, Tin Whisker Testing and Modeling showing a method to do this based on the electrical components used and printed circuit board topology.