The all-terminal reliability and K-terminal reliability of networks are oft
en considered as separate problems. We use the partition lattice of the ver
tex set of an undirected graph to show that these reliability measures are
closely related. As an application of the presented approach, a formula for
the K-terminal reliability polynomial of the complete graph and Buzacott's
node partition formula are derived. (C) 1999 Elsevier Science B.V. All rig
hts reserved.