I have got couple of comments to be updated

<?xml version="1.0" encoding="ISO-859-1"?>
>>encoding information is wrong, that should be a typo to ISO-8589-1

opendir(DIR, ".");
>> return status should be checked
>> opendir(DIR, ".") or die "Unable to open directory <$!>\n";

closedir(DIR);
>> closing the directory also might fail, its better to check the return status
>> closedir(DIR) or die "Unable to close the directory <$!>\n";

while ($a ne "y")
>> What if the user is not interested to process the xml files. This seems to be forcing user to select an option to process the files
>> If this is going to be modified in such a way that user can input either "y" or "n", then prefetching of xml files into array should be done only after based on user's input

$a = <STDIN>;    chop $a;
>> I think this is better chomp( $a = <STDIN );

my $xs1 = XML::Simple->new();
>> there is no need to create an object for each and every file
>> same thing applies to other objects repeatitively created where just one instance can be made use of.