$ perl -Mstrict -w

my @arr = (
  'bla',
  '<SW-SYSCOND>((<SW-SYSTEMCONST-CODED-REF>S1B1_SY</SW-SYSTEMCONST-CODED-REF> == 2) || (<SW-SYSTEMCONST-CODED-REF>S1B2_SY</SW-SYSTEMCONST-CODED-REF> == 2) || (<SW-SYSTEMCONST-CODED-REF>S2B1_SY</SW-SYSTEMCONST-CODED-REF> == 2) || (<SW-SYSTEMCONST-CODED-REF>S3B1_SY</SW-SYSTEMCONST-CODED-REF> == 2) ||<SW-SYSTEMCONST-CODED-REF>K1_SC</SW-SYSTEMCONST-CODED-REF>)</SW-SYSCOND>',
);

for  ( @arr ) {
  if ( m/(<SW-SYSCOND>.*<\/SW-SYSCOND>)/gi ) {
    print "yes\n";
  }
  else {
    print "no\n";
  }
}

^D
no
yes