#!/usr/bin/perl -w
use strict;

use XML::XPath;

my $file = 'available_batchnyyn.xml';
my $xp = XML::XPath->new(filename=>$file);

# /AvailableBatch/Available is faster than //Available
my @available = $xp->findnodes('/AvailableBatch/Available'); 
foreach my $available (@available)
  { my $part= $available->findvalue( './Part[1]'); # the [1] is not really needed
    my $qty= $available->findvalue( './Qty[1]');
    $part=~ s{\s+$}{};                             # you might need to trim all values
    print "part $part - qty: $qty\n";
  }