feat(assignment_rule): add weighted distribution strategy (#37741)

frappe/automation/doctype/assignment_rule/assignment_rule.json

@@ -26,7 +26,10 @@
   "rule",
   "field",
   "users",
-  "last_user"
+  "weighted_users",
+  "column_break_mkgo",
+  "last_user",
+  "current_index"
  ],
  "fields": [
   {
@@ -96,15 +99,15 @@
    "fieldtype": "Select",
    "in_list_view": 1,
    "label": "Rule",
-   "options": "Round Robin\nLoad Balancing\nBased on Field",
+   "options": "Round Robin\nLoad Balancing\nBased on Field\nWeighted Distribution",
    "reqd": 1
   },
   {
-   "depends_on": "eval: doc.rule !== 'Based on Field'",
+   "depends_on": "eval:in_list(['Round Robin', \"Load Balancing\"],  doc.rule)",
    "fieldname": "users",
    "fieldtype": "Table MultiSelect",
    "label": "Users",
-   "mandatory_depends_on": "eval: doc.rule !== 'Based on Field'",
+   "mandatory_depends_on": "eval:in_list(['Round Robin', \"Load Balancing\"],  doc.rule)",
    "options": "Assignment Rule User"
   },
   {
@@ -150,12 +153,31 @@
    "fieldtype": "Select",
    "label": "Field",
    "mandatory_depends_on": "eval: doc.rule == 'Based on Field'"
+  },
+  {
+   "depends_on": "eval:doc.rule=='Weighted Distribution'",
+   "fieldname": "current_index",
+   "fieldtype": "Int",
+   "label": "Current Index",
+   "read_only": 1
+  },
+  {
+   "fieldname": "column_break_mkgo",
+   "fieldtype": "Column Break"
+  },
+  {
+   "depends_on": "eval:doc.rule=='Weighted Distribution'",
+   "fieldname": "weighted_users",
+   "fieldtype": "Table",
+   "label": "Users",
+   "mandatory_depends_on": "eval:doc.rule=='Weighted Distribution'",
+   "options": "Assignment Rule User"
   }
  ],
  "grid_page_length": 50,
  "index_web_pages_for_search": 1,
  "links": [],
- "modified": "2025-08-25 17:09:11.644603",
+ "modified": "2026-03-03 13:08:12.561504",
  "modified_by": "Administrator",
  "module": "Automation",
  "name": "Assignment Rule",

frappe/automation/doctype/assignment_rule/assignment_rule.py

@@ -20,14 +20,13 @@ class AssignmentRule(Document):
 
 	if TYPE_CHECKING:
 		from frappe.automation.doctype.assignment_rule_day.assignment_rule_day import AssignmentRuleDay
-		from frappe.automation.doctype.assignment_rule_user.assignment_rule_user import (
+		from frappe.automation.doctype.assignment_rule_user.assignment_rule_user import AssignmentRuleUser
-			AssignmentRuleUser,
-		)
 		from frappe.types import DF
 
 		assign_condition: DF.Code
 		assignment_days: DF.Table[AssignmentRuleDay]
 		close_condition: DF.Code | None
+		current_index: DF.Int
 		description: DF.SmallText
 		disabled: DF.Check
 		document_type: DF.Link
@@ -35,9 +34,10 @@ class AssignmentRule(Document):
 		field: DF.Literal[None]
 		last_user: DF.Link | None
 		priority: DF.Int
-		rule: DF.Literal["Round Robin", "Load Balancing", "Based on Field"]
+		rule: DF.Literal["Round Robin", "Load Balancing", "Based on Field", "Weighted Distribution"]
 		unassign_condition: DF.Code | None
 		users: DF.TableMultiSelect[AssignmentRuleUser]
+		weighted_users: DF.Table[AssignmentRuleUser]
 	# end: auto-generated types
 
 	def validate(self):
@@ -80,25 +80,25 @@ class AssignmentRule(Document):
 
 		user = self.get_user(doc)
 
-		if user:
+		if not user or not frappe.db.exists("User", user):
-			assign_to.add(
+			return False
-				dict(
-					assign_to=[user],
-					doctype=doc.get("doctype"),
-					name=doc.get("name"),
-					description=frappe.render_template(self.description, doc),
-					assignment_rule=self.name,
-					notify=True,
-					date=doc.get(self.due_date_based_on) if self.due_date_based_on else None,
-				),
-				ignore_permissions=True,
-			)
 
-			# set for reference in round robin
+		assign_to.add(
-			self.db_set("last_user", user)
+			dict(
-			return True
+				assign_to=[user],
+				doctype=doc.get("doctype"),
+				name=doc.get("name"),
+				description=frappe.render_template(self.description, doc),
+				assignment_rule=self.name,
+				notify=True,
+				date=doc.get(self.due_date_based_on) if self.due_date_based_on else None,
+			),
+			ignore_permissions=True,
+		)
 
-		return False
+		# set for reference in round robin
+		self.db_set("last_user", user)
+		return True
 
 	def clear_assignment(self, doc):
 		"""Clear assignments"""
@@ -122,6 +122,8 @@ class AssignmentRule(Document):
 			return self.get_user_load_balancing()
 		elif self.rule == "Based on Field":
 			return self.get_user_based_on_field(doc)
+		elif self.rule == "Weighted Distribution":
+			return self.get_weighted_user()
 
 	def get_user_round_robin(self):
 		"""
@@ -167,6 +169,33 @@ class AssignmentRule(Document):
 		if frappe.db.exists("User", val):
 			return val
 
+	def get_weighted_user(self):
+		"""
+		Assign to the user based on weights assigned to users
+		Each rule maintains its own counter.
+		"""
+		users = [(d.user, d.weight or 1) for d in self.weighted_users if d.user]
+		if not users:
+			return None
+
+		total_weight = sum(weight for _, weight in users)
+		if total_weight <= 0:
+			return None
+
+		current_index = (
+			frappe.db.get_value("Assignment Rule", self.name, "current_index", for_update=True) or 0
+		)
+		slot = current_index % total_weight
+
+		cumulative_weight = 0
+		for user, weight in users:
+			cumulative_weight += weight
+			if slot < cumulative_weight:
+				frappe.db.set_value(
+					"Assignment Rule", self.name, "current_index", current_index + 1, update_modified=False
+				)
+				return user
+
 	def safe_eval(self, fieldname, doc):
 		try:
 			if self.get(fieldname):

frappe/automation/doctype/assignment_rule/test_assignment_rule.py

@@ -113,6 +113,26 @@ class TestAutoAssign(IntegrationTestCase):
 				len(frappe.get_all("ToDo", dict(allocated_to=user, reference_type=TEST_DOCTYPE))), 10
 			)
 
+	def test_weighted_distribution(self):
+		self.assignment_rule.rule = "Weighted Distribution"
+		self.assignment_rule.weighted_users.clear()
+		self.assignment_rule.append("weighted_users", dict(user="test@example.com", weight=1))
+		self.assignment_rule.append("weighted_users", dict(user="test1@example.com", weight=2))
+		self.assignment_rule.save()
+
+		for _ in range(5):
+			_make_test_record(public=1)
+
+		# check if users are assigned based on weights (out of 5,
+		# test@example.com should have 2 assignments and test1@example.com should have 3 assignments )
+		self.assertEqual(
+			len(frappe.get_all("ToDo", dict(allocated_to="test@example.com", reference_type=TEST_DOCTYPE))), 2
+		)
+		self.assertEqual(
+			len(frappe.get_all("ToDo", dict(allocated_to="test1@example.com", reference_type=TEST_DOCTYPE))),
+			3,
+		)
+
 	def test_assingment_on_guest_submissions(self):
 		"""Sometimes documents are inserted as guest, check if assignment rules run on them. Use case: Web Forms"""
 		with self.set_user("Guest"):

frappe/automation/doctype/assignment_rule_user/assignment_rule_user.json

@@ -5,7 +5,8 @@
  "editable_grid": 1,
  "engine": "InnoDB",
  "field_order": [
-  "user"
+  "user",
+  "weight"
  ],
  "fields": [
   {
@@ -15,20 +16,29 @@
    "label": "User",
    "options": "User",
    "reqd": 1
+  },
+  {
+   "default": "1",
+   "fieldname": "weight",
+   "fieldtype": "Int",
+   "in_list_view": 1,
+   "label": "Weight"
   }
  ],
+ "grid_page_length": 50,
  "index_web_pages_for_search": 1,
  "istable": 1,
  "links": [],
- "modified": "2024-03-23 16:01:27.847608",
+ "modified": "2026-03-03 12:30:01.394107",
  "modified_by": "Administrator",
  "module": "Automation",
  "name": "Assignment Rule User",
  "owner": "Administrator",
  "permissions": [],
  "quick_entry": 1,
+ "row_format": "Dynamic",
  "sort_field": "creation",
  "sort_order": "DESC",
  "states": [],
  "track_changes": 1
-}
+}

frappe/automation/doctype/assignment_rule_user/assignment_rule_user.py

@@ -18,6 +18,7 @@ class AssignmentRuleUser(Document):
 		parentfield: DF.Data
 		parenttype: DF.Data
 		user: DF.Link
+		weight: DF.Int
 	# end: auto-generated types
 
 	pass