diff --git a/plm_compare_bom/__manifest__.py b/plm_compare_bom/__manifest__.py
index 61435495..4da9fb15 100644
--- a/plm_compare_bom/__manifest__.py
+++ b/plm_compare_bom/__manifest__.py
@@ -20,7 +20,7 @@
 ##############################################################################
 {
     "name": "PLM Compare Bom",
-    "version": "16.0.1",
+    "version": "16.0.2",
     "author": "OmniaSolutions",
     "website": "https://odooplm.omniasolutions.website",
     "category": "Manufacturing/Product Lifecycle Management (PLM)",
diff --git a/plm_compare_bom/models/compare_bom.py b/plm_compare_bom/models/compare_bom.py
index 6f4fbb02..586c5137 100755
--- a/plm_compare_bom/models/compare_bom.py
+++ b/plm_compare_bom/models/compare_bom.py
@@ -204,20 +204,46 @@ def update_bom(self):
         mrp_bom_line = self.env['mrp.bom.line']
         for plm_compare_bom_id in self:
             for plm_missing_id in plm_compare_bom_id.anotinb.filtered(lambda x: x.reason == 'new'):
-                mrp_bom_line.create({
-                    'bom_id': self.bom_id1.id,
-                    'product_qty': plm_missing_id.itemqty,
-                    'product_id': plm_missing_id.part_id.id,
-                    'type': self.bom_id1.type,
-                    'itemnum': len(self.bom_id1.bom_line_ids) + 1})
+                existing_line = mrp_bom_line.search([
+                    ('bom_id', '=', self.bom_id1.id),
+                    ('product_id', '=', plm_missing_id.part_id.id),
+                    ('itemnum', '=', plm_missing_id.itemnum)
+                ], limit=1)
+
+                if existing_line:
+                    if self.compute_type == "num_qty":
+                        existing_line.product_qty = plm_missing_id.itemqty
+                    else:
+                        existing_line.product_qty += plm_missing_id.itemqty
+                else:
+                    mrp_bom_line.create({
+                        'bom_id': self.bom_id1.id,
+                        'product_qty': plm_missing_id.itemqty,
+                        'product_id': plm_missing_id.part_id.id,
+                        'type': self.bom_id1.type,
+                        'itemnum': plm_missing_id.itemnum
+                    })
                 plm_missing_id.reason = 'added'
             for plm_adding_id in plm_compare_bom_id.bnotina.filtered(lambda x: x.reason == 'new'):
-                mrp_bom_line.create({
-                    'bom_id': self.bom_id2.id,
-                    'product_qty': plm_adding_id.itemqty,
-                    'product_id': plm_adding_id.part_id.id,
-                    'type': self.bom_id2.type,
-                    'itemnum': len(self.bom_id2.bom_line_ids) + 1})
+                existing_line = mrp_bom_line.search([
+                    ('bom_id', '=', self.bom_id2.id),
+                    ('product_id', '=', plm_adding_id.part_id.id),
+                    ('itemnum', '=', plm_adding_id.itemnum)
+                ], limit=1)
+
+                if existing_line:
+                    if self.compute_type == "num_qty":
+                        existing_line.product_qty = plm_adding_id.itemqty
+                    else:
+                        existing_line.product_qty += plm_adding_id.itemqty
+                else:
+                    mrp_bom_line.create({
+                        'bom_id': self.bom_id2.id,
+                        'product_qty': plm_adding_id.itemqty,
+                        'product_id': plm_adding_id.part_id.id,
+                        'type': self.bom_id2.type,
+                        'itemnum': plm_adding_id.itemnum
+                    })
                 plm_adding_id.reason = 'added'
             for mrp_bom_line_id in plm_compare_bom_id.bom_line_id_to_delete:
                 mrp_bom_line_id.unlink()