  We introduce in this paper the notion of noncommutative Serre fibration
(shortly, NCSF) and show that up to homotopy, every NCCW complex morphism is
some noncommutative Serre fibration. We then deduce a six-term exact sequence
for the periodic cyclic homology and for K-theory of an arbitrary
noncommutative Serre fibration. We also show how to use this technique to
compute K-theory and cyclic theory of some noncommutative quotients.
