Just a note of caution. I'm not familiar with your use-case, but might simply deleting the  / (forward-slash) delimiters be ambiguous? Consider  'POS1/23/4' versus  'POS12/3/4' etc. Maybe better to replace with an innocuous character (note: no  /d modifier needed here):

c:\@Work\Perl>perl -wMstrict -le
"use 5.014;
 ;;
 my $s = 'POS1/23/4';
 ;;
 my $t = $s =~ tr{/}{-}r;
 print qq{'$s' -> '$t'};
"
'POS1/23/4' -> 'POS1-23-4'
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Update: See  tr/// in Quote-Like Operators section in perlop.