  One of the most studied models of SAT is random SAT. In this model, instances
are composed from clauses chosen uniformly randomly and independently of each
other. This model may be unsatisfactory in that it fails to describe various
features of SAT instances, arising in real-world applications. Various
modifications have been suggested to define models of industrial SAT. Here, we
focus mainly on the aspect of community structure. Namely, here the set of
variables consists of a number of disjoint communities, and clauses tend to
consist of variables from the same community. Thus, we suggest a model of
random industrial SAT, in which the central generalization with respect to
random SAT is the additional community structure.
  There has been a lot of work on the satisfiability threshold of random
$k$-SAT, starting with the calculation of the threshold of $2$-SAT, up to the
recent result that the threshold exists for sufficiently large $k$.
  In this paper, we endeavor to study the satisfiability threshold for the
proposed model of random industrial SAT. Our main result is that the threshold
in this model tends to be smaller than its counterpart for random SAT.
Moreover, under some conditions, this threshold even vanishes.
