Perl Script Error : Can't call method "execute_flow" without a package or object reference

[Fatema M]

Hi,
 I am facing an error while executing the Perl script, its compilation fails
with the following error
   "Can't call method "execute_flow" without a package or object reference
at <addr> "

Code Snippet:

 require 'test_data';

$SCRIPT_ID =
"A1155.4.1.1-Checking_RDI-V_detection_and_clearing_on_the_vtSpan_wh
ich_does_not_provide_an_external_source_of_clock_signal._1.p";
require "$ENV{INCLUDES_PATH}includes.pm";
require 'Interface_Engine.pm';
require "$ENV{PATH_TO_LIBRARIES}/is95_lib/CRC_calculation.pm";
use lib "$ENV{O3LIBDIR}";
require "$ENV{SDUCONFIGPATH}/sysconfig.pm";

use netElement::vpu;

&getSysConfig ($O3_VPU_ID , \%vpu);
$vpu=new vpu(\%vpu);

#&comment("Lock /neApps-1 in order to change APS mode.");
@vpuReport = ();
%my_step = ('lock:device'=> ["NEAPPS-0-0-0-1"]);
$rc = $vpu->execute_flow(\...@my_step,\...@vpureport,"$REPORT_STATUS");  -- 
*ERROR
HERE !!*
$vpu->report(\...@vpureport, \%REPORT_FORMAT);
if ($rc) {
        $fail++;
}
if ($fail && $REPORT_STATUS eq "fail-on-mismatch"){
        exit("Test_Failed");
}


#&comment("Verify that /neApps-1 is locked.");
@vpuReport = ();
@my_step = ('verify:state'=> ["NEAPPS-0-0-0-1" => {
        "AdminState" => "L",
        "OpState" => "D",
        "UsgState" => "I",
        "CtrlState" => "N",
        "AvailState" => "N",
        }]);

$rc = $vpu->execute_flow(\...@my_step,\...@vpureport,"$REPORT_STATUS");  -- 
*ERROR
HERE !*
$vpu->report(\...@vpureport, \%REPORT_FORMAT);
if ($rc) {
        $fail++;
}
if ($fail && $REPORT_STATUS eq "fail-on-mismatch"){
        exit("Test_Failed");
}

The script fails at all "execute_flow" methods.

PS: I am fairly new to Perl scripting and was not able to find the mistake
based on similar posts.