#!/usr/bin/perl

use strict;
use warnings;

use Data::Dumper;

my $data = [
          {
            'prod_order' => '702164',
            'operation' => '10',
            'machine' => 'W01',
            
          },
          {
            'prod_order' => '702164',
            'operation' => '10',
            'machine' => 'W02',
          },
            {
            'prod_order' => '702164',
            'operation' => '10',
            'machine' => 'W01',
          },
          {
            'prod_order' => '702164',
            'operation' => '10',
            'machine' => 'W02',
          },
          {
            'prod_order' => '702164',
            'operation' => '10',
            'machine' => 'W03',
          },
          {
            'prod_order' => '702164',
            'operation' => '100',
            'machine' => 'W03',
          }
        ];

my %hash = ();

my @newdata = grep { ! $hash{ $_->{operation} . $_->{machine} }++ } @$data;

print Dumper @newdata;