my @array1 = (1..5); # N
my @array2 = qw/a b/;

for my $val1 (@array1) {
	# Start N processes here that can run in parallel
	# Each process outputs data to its own separate file
	# I will need it in the future

	for my $val2 (@array2) {
		# For each of the N processes, wait until it is done, 
		# then start 2 parallel processes which use
		# the output data as input
		# Save the output of each process separately to 2N files
		# (two files with N elements would be better, but as I 
		# couldn't figure that out, I just postprocess the data ;-)
	}
}
# "waitallchildren" or equivalent

# Postprocess step to reduce the final output to 2 files