That doesn't look like code. But your problem intrigued me. The below code gets you the duplicates removed similar to what you're looking for, but you'll need to improve it a bit* to get the exact data format you're after.

#!/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;
[download]

Output:

$VAR1 = {
          'operation' => '10',
          'prod_order' => '702164',
          'machine' => 'W01'
        };
$VAR2 = {
          'operation' => '10',
          'prod_order' => '702164',
          'machine' => 'W02'
        };
$VAR3 = {
          'operation' => '10',
          'prod_order' => '702164',
          'machine' => 'W03'
        };
$VAR4 = {
          'operation' => '100',
          'prod_order' => '702164',
          'machine' => 'W03'
        };
[download]

* FYI, since the OP didn't show us any effort, I figure if they really need the result as $data = [ { .. => .. }, { .. => .. } ]; they can add a couple of characters and change a few sigils in what I've posted.

s**lil*;  $*=join'',sort split q**;  s;.*;grr; &&s+(.(.)).+$2$1+; $; =
qq-$_-;s,.*,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$*,$/)
[download]

Thanks a lot for the solution

# Create a lookuptable to store found items
my %hash = ();

# Iterate over the data-array (thats what grep does here), and add the
+ item to newdata, and set the found item in the lookup table. When th
+e new item is in the lookup table, don't add it again.
my @newdata = grep { ! $hash{ $_->{operation} . $_->{machine} }++ } @$
+data;

# more readable than grep (to my opinion,probably not to all others :)
+ ), but basically the same:
my %hash = ();
my @newdata;
foreach my $item (@{$data}) {
 if (! $hash{ $item->{operation} . $item->{machine} } ) {
    $hash{ $item->{operation} . $item->{machine} } = 1 ;
    push @newdata, $item;
 }
}
[download]