diff --git a/app/Models/WorkGroupMaster.php b/app/Models/WorkGroupMaster.php
index 2b454e7..806bd70 100644
--- a/app/Models/WorkGroupMaster.php
+++ b/app/Models/WorkGroupMaster.php
@@ -30,6 +30,11 @@ class WorkGroupMaster extends Model
         return $this->hasMany(Machine::class, 'work_group_master_id');
     }
 
+    public function productCharacteristicsMasters()
+    {
+        return $this->hasMany(ProductCharacteristicsMaster::class);
+    }
+
     // public function rejectReasons()
     // {
     //     return $this->hasMany(RejectReason::class, 'work_group_master_id', 'id');