diff --git a/app/Http/Controllers/ObdController.php b/app/Http/Controllers/ObdController.php
index e95c7c15d..78563f07c 100644
--- a/app/Http/Controllers/ObdController.php
+++ b/app/Http/Controllers/ObdController.php
@@ -6,6 +6,7 @@ use App\Models\Item;
 use App\Models\Plant;
 use App\Models\WeightValidation;
 use Illuminate\Http\Request;
+use Str;
 
 class ObdController extends Controller
 {
@@ -51,6 +52,14 @@ class ObdController extends Controller
                 return response($message, 400)->header('Content-Type', 'text/plain');
             }
 
+             // OBD Number validation
+            $obdNumber = $data['obd_number'];
+            if (Str::length($obdNumber) < 8 || !ctype_alnum($obdNumber))
+            {
+                return response("ERROR: OBD Number should contain minimum 8 digits", 400)
+                    ->header('Content-Type', 'text/plain');
+            }
+
             // Lookup plant_id by plant_name
             $plantId = Plant::where('name', $data['plant_name'])->value('id');
             if (!$plantId) {
@@ -63,7 +72,12 @@ class ObdController extends Controller
 
             foreach ($data['line_numbers'] as $line)
             {
-                if (empty($line['line_number'])) continue;
+                //if (empty($line['line_number'])) continue;
+                //!isset($line['line_number']) ||
+                if ($line['line_number'] == '' || $line['line_number'] == null) {
+                    return response("ERROR: Line Number can't be empty", 400)
+                        ->header('Content-Type', 'text/plain');
+                }
 
                 $exists = WeightValidation::where('plant_id', $plantId)
                     ->where('obd_number', $data['obd_number'])
@@ -76,6 +90,45 @@ class ObdController extends Controller
                     continue;
                 }
 
+
+                // $mandatoryFields = ['vehicle_number', 'bundle_number', 'picked_weight', 'scanned_by'];
+                // $missingFields = [];
+                // foreach ($mandatoryFields as $field) {
+                //     if ($line[$field] == '' || $line[$field] == null) {   //!isset($line[$field]) ||
+                //         $missingFields[] = $field;
+                //     }
+                // }
+                // if (!empty($missingFields)) {
+                //     $message = "ERROR: Missing or empty field(s): " . implode(', ', $missingFields) .
+                //             " for line_number " . $line['line_number'];
+                //     return response($message, 400)->header('Content-Type', 'text/plain');
+                // }
+
+                $mandatoryFields = ['vehicle_number', 'bundle_number', 'picked_weight', 'scanned_by'];
+                $missingFields = [];
+
+                foreach ($mandatoryFields as $field) {
+                    if ($line[$field] == '' || $line[$field] == null) {
+                        // Convert field name to a more readable format, e.g. vehicle_number -> Vehicle Number
+                        $missingFields[] = ucwords(str_replace('_', ' ', $field));
+                    }
+                }
+
+                if (!empty($missingFields)) {
+                    if (count($missingFields) == 1)
+                    {
+                        $fieldsString = $missingFields[0];
+                    }
+                    else
+                    {
+                        $lastField = array_pop($missingFields);
+                        $fieldsString = implode(', ', $missingFields) . ' and ' . $lastField;
+                    }
+
+                    $message = "ERROR: " . $fieldsString . " can't be empty for line_number " . $line['line_number'];
+                    return response($message, 400)->header('Content-Type', 'text/plain');
+                }
+
                 $count = WeightValidation::where([
                         'plant_id'   => $plantId,
                         'obd_number' => $data['obd_number'],
@@ -190,13 +243,24 @@ class ObdController extends Controller
                 ->header('Content-Type', 'text/plain');
         }
 
-        $plantName = $request->header('plant-name'); // use lowercase
+        $plantName = $request->header('plant-name');
         $obdNumber = $request->header('obd-number');
 
-        if (empty($plantName) || empty($obdNumber)) {
-            return response("ERROR: Missing required headers (plant_name, obd_number)", 400)
+        if (empty($plantName))
+        {
+            return response("ERROR: Plant Name can't be empty", 400)
                 ->header('Content-Type', 'text/plain');
         }
+        else if(empty($obdNumber))
+        {
+            return response("ERROR: OBD Number can't be empty", 400)
+            ->header('Content-Type', 'text/plain');
+        }
+        else if(Str::length($obdNumber) < 8 || !ctype_alnum($obdNumber))
+        {
+            return response("ERROR: OBD Number should contain minimum 8 digits", 400)
+            ->header('Content-Type', 'text/plain');
+        }
 
         // Fetch the plant id by name
         $plantId = Plant::where('name', $plantName)->value('id');
@@ -206,12 +270,30 @@ class ObdController extends Controller
                 ->header('Content-Type', 'text/plain');
         }
 
+        // $records = WeightValidation::where('plant_id', $plantId)
+        //     ->where('obd_number', $obdNumber)
+        //     ->get();
+         // Fetch and filter records where vehicle_number is empty or null
+
+         $exists = WeightValidation::where('plant_id', $plantId)
+        ->where('obd_number', $obdNumber)
+        ->exists();
+
+        if (!$exists)
+        {
+            return response("ERROR: OBD number $obdNumber does not exist for plant '$plantName'", 404)
+                ->header('Content-Type', 'text/plain');
+        }
+
         $records = WeightValidation::where('plant_id', $plantId)
-            ->where('obd_number', $obdNumber)
-            ->get();
+        ->where('obd_number', $obdNumber)
+        ->get()
+        ->filter(function ($record) {
+            return $record->vehicle_number == '' || $record->vehicle_number == null;
+        });
 
         if ($records->isEmpty()) {
-            return response("ERROR: No records found", 404)->header('Content-Type', 'text/plain');
+            return response("SUCCESS: Already scanning process completed for the OBD Number", 200)->header('Content-Type', 'text/plain');
         }
 
         $itemIds = $records->pluck('item_id')->unique();
@@ -234,7 +316,7 @@ class ObdController extends Controller
                             'Heat_Number' => $item->heat_number ?? "",
                             'Actual_Weight' => $item->obd_weight ?? "",
                         ];
-                    })->toArray()
+                    })->values()->toArray()
                 ]
             ]
         ];