  We study how the addition of defects in an otherwise uniform Josehpson
junction array modifies the critical current of the array, by numerically
solving the system of coupled Josephson equations. Our results confirm the
existence of two different regimes, depending on the normalized maximum
Josephson current of each junction, $i_{\rm max}$: for large $i_{\rm max}$, the
defects deteriorate partially the critical state of the uniform array and so
decrease the critical current, while for low values of $i_{\rm max}$, the
defects help the formation of the critical state, which leads to an enhancement
of critical current. The results are discussed in comparison with the behavior
of type-II superconductors, for which the inclusion of defects always results
in an enhancement of the critical current.
