app/Models/Item.php

@@ -74,6 +74,11 @@ class Item extends Model
         return $this->hasMany(RequestCharacteristic::class, 'item_id', 'id');
     }
 
+    public function productionCharacteristics()
+    {
+        return $this->hasMany(ProductionCharacteristic::class, 'item_id', 'id');
+    }
+
     public function weightValidations()
     {
         return $this->hasMany(WeightValidation::class);

app/Models/Line.php

@@ -71,6 +71,11 @@ class Line extends Model
         return $this->hasMany(CharacteristicValue::class);
     }
 
+    public function productionCharacteristics()
+    {
+        return $this->hasMany(ProductionCharacteristic::class);
+    }
+
     public function workGroup1()
     {
         return $this->belongsTo(WorkGroupMaster::class, 'work_group1_id', 'id');

app/Models/Machine.php

@@ -53,6 +53,11 @@ class Machine extends Model
         return $this->hasMany(RequestCharacteristic::class, 'machine_id', 'id');
     }
 
+    public function productionCharacteristics()
+    {
+        return $this->hasMany(ProductionCharacteristic::class, 'machine_id', 'id');
+    }
+
     public function testingPanelReadings()
     {
         return $this->hasMany(TestingPanelReading::class);

app/Models/Plant.php

@@ -133,6 +133,11 @@ class Plant extends Model
         return $this->hasMany(RequestCharacteristic::class, 'plant_id', 'id');
     }
 
+    public function productionCharacteristics()
+    {
+        return $this->hasMany(ProductionCharacteristic::class, 'plant_id', 'id');
+    }
+
     public function users()
     {
         return $this->hasMany(User::class, 'plant_id', 'id');