diff --git a/erpnext/maintenance/doctype/maintenance_schedule/maintenance_schedule.py b/erpnext/maintenance/doctype/maintenance_schedule/maintenance_schedule.py
index 2ffae1a..07d928c 100644
--- a/erpnext/maintenance/doctype/maintenance_schedule/maintenance_schedule.py
+++ b/erpnext/maintenance/doctype/maintenance_schedule/maintenance_schedule.py
@@ -1,7 +1,6 @@
 # Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
 # License: GNU General Public License v3. See license.txt
 
-
 import frappe
 from frappe import _, throw
 from frappe.utils import add_days, cint, cstr, date_diff, formatdate, getdate
@@ -306,13 +305,18 @@
 					return schedule.name
 
 @frappe.whitelist()
-def update_serial_nos(s_id):
-	serial_nos = frappe.db.get_value('Maintenance Schedule Detail', s_id, 'serial_no')
+def get_serial_nos_from_schedule(item_code, schedule=None):
+	serial_nos = []
+	if schedule:
+		serial_nos = frappe.db.get_value('Maintenance Schedule Item', {
+			'parent': schedule,
+			'item_code': item_code
+		}, 'serial_no')
+
 	if serial_nos:
 		serial_nos = get_serial_nos(serial_nos)
-		return serial_nos
-	else:
-		return False
+
+	return serial_nos
 
 @frappe.whitelist()
 def make_maintenance_visit(source_name, target_doc=None, item_name=None, s_id=None):
@@ -320,12 +324,9 @@
 
 	def update_status_and_detail(source, target, parent):
 		target.maintenance_type = "Scheduled"
-		target.maintenance_schedule = source.name
 		target.maintenance_schedule_detail = s_id
 
-	def update_sales_and_serial(source, target, parent):
-		sales_person = frappe.db.get_value('Maintenance Schedule Detail', s_id, 'sales_person')
-		target.service_person = sales_person
+	def update_serial(source, target, parent):
 		serial_nos = get_serial_nos(target.serial_no)
 		if len(serial_nos) == 1:
 			target.serial_no = serial_nos[0]
@@ -346,7 +347,10 @@
 		"Maintenance Schedule Item": {
 			"doctype": "Maintenance Visit Purpose",
 			"condition": lambda doc: doc.item_name == item_name,
-			"postprocess": update_sales_and_serial
+			"field_map": {
+				"sales_person": "service_person"
+			},
+			"postprocess": update_serial
 		}
 	}, target_doc)
 
diff --git a/erpnext/maintenance/doctype/maintenance_schedule/test_maintenance_schedule.py b/erpnext/maintenance/doctype/maintenance_schedule/test_maintenance_schedule.py
index 5017126..4d3c3f4 100644
--- a/erpnext/maintenance/doctype/maintenance_schedule/test_maintenance_schedule.py
+++ b/erpnext/maintenance/doctype/maintenance_schedule/test_maintenance_schedule.py
@@ -7,8 +7,11 @@
 from frappe.utils.data import add_days, formatdate, today
 
 from erpnext.maintenance.doctype.maintenance_schedule.maintenance_schedule import (
+	get_serial_nos_from_schedule,
 	make_maintenance_visit,
 )
+from erpnext.stock.doctype.item.test_item import create_item
+from erpnext.stock.doctype.stock_entry.test_stock_entry import make_serialized_item
 
 # test_records = frappe.get_test_records('Maintenance Schedule')
 
@@ -80,6 +83,42 @@
 		#checks if visit status is back updated in schedule
 		self.assertTrue(ms.schedules[1].completion_status, "Partially Completed")
 
+	def test_serial_no_filters(self):
+		# Without serial no. set in schedule -> returns None
+		item_code = "_Test Serial Item"
+		make_serial_item_with_serial(item_code)
+		ms = make_maintenance_schedule(item_code=item_code)
+		ms.submit()
+
+		s_item = ms.schedules[0]
+		mv = make_maintenance_visit(source_name=ms.name, item_name=item_code, s_id=s_item.name)
+		mvi = mv.purposes[0]
+		serial_nos = get_serial_nos_from_schedule(mvi.item_name, ms.name)
+		self.assertEqual(serial_nos, None)
+
+		# With serial no. set in schedule -> returns serial nos.
+		make_serial_item_with_serial(item_code)
+		ms = make_maintenance_schedule(item_code=item_code, serial_no="TEST001, TEST002")
+		ms.submit()
+
+		s_item = ms.schedules[0]
+		mv = make_maintenance_visit(source_name=ms.name, item_name=item_code, s_id=s_item.name)
+		mvi = mv.purposes[0]
+		serial_nos = get_serial_nos_from_schedule(mvi.item_name, ms.name)
+		self.assertEqual(serial_nos, ["TEST001", "TEST002"])
+
+		frappe.db.rollback()
+
+def make_serial_item_with_serial(item_code):
+	serial_item_doc = create_item(item_code, is_stock_item=1)
+	if not serial_item_doc.has_serial_no or not serial_item_doc.serial_no_series:
+		serial_item_doc.has_serial_no = 1
+		serial_item_doc.serial_no_series = "TEST.###"
+		serial_item_doc.save(ignore_permissions=True)
+	active_serials = frappe.db.get_all('Serial No', {"status": "Active", "item_code": item_code})
+	if len(active_serials) < 2:
+		make_serialized_item(item_code=item_code)
+
 def get_events(ms):
 	return frappe.get_all("Event Participants", filters={
 			"reference_doctype": ms.doctype,
@@ -87,17 +126,18 @@
 			"parenttype": "Event"
 		})
 
-def make_maintenance_schedule():
+def make_maintenance_schedule(**args):
 	ms = frappe.new_doc("Maintenance Schedule")
 	ms.company = "_Test Company"
 	ms.customer = "_Test Customer"
 	ms.transaction_date = today()
 
 	ms.append("items", {
-		"item_code": "_Test Item",
+		"item_code": args.get("item_code") or "_Test Item",
 		"start_date": today(),
 		"periodicity": "Weekly",
 		"no_of_visits": 4,
+		"serial_no": args.get("serial_no"),
 		"sales_person": "Sales Team",
 	})
 	ms.insert(ignore_permissions=True)
diff --git a/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.js b/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.js
index d2197a6..72686e7 100644
--- a/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.js
+++ b/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.js
@@ -2,52 +2,54 @@
 // License: GNU General Public License v3. See license.txt
 
 frappe.provide("erpnext.maintenance");
-var serial_nos = [];
 frappe.ui.form.on('Maintenance Visit', {
-	refresh: function (frm) {
-		//filters for serial_no based on item_code
-		frm.set_query('serial_no', 'purposes', function (frm, cdt, cdn) {
-			let item = locals[cdt][cdn];
-			if (serial_nos) {
-				return {
-					filters: {
-						'item_code': item.item_code,
-						'name': ["in", serial_nos]
-					}
-				};
-			} else {
-				return {
-					filters: {
-						'item_code': item.item_code
-					}
-				};
-			}
-		});
-	},
 	setup: function (frm) {
 		frm.set_query('contact_person', erpnext.queries.contact_query);
 		frm.set_query('customer_address', erpnext.queries.address_query);
 		frm.set_query('customer', erpnext.queries.customer);
 	},
-	onload: function (frm, cdt, cdn) {
-		let item = locals[cdt][cdn];
+	onload: function (frm) {
+		// filters for serial no based on item code
 		if (frm.doc.maintenance_type === "Scheduled") {
-			const schedule_id = item.purposes[0].prevdoc_detail_docname || frm.doc.maintenance_schedule_detail;
+			let item_code = frm.doc.purposes[0].item_code;
 			frappe.call({
-				method: "erpnext.maintenance.doctype.maintenance_schedule.maintenance_schedule.update_serial_nos",
+				method: "erpnext.maintenance.doctype.maintenance_schedule.maintenance_schedule.get_serial_nos_from_schedule",
 				args: {
-					s_id: schedule_id
-				},
-				callback: function (r) {
-					serial_nos = r.message;
+					schedule: frm.doc.maintenance_schedule,
+					item_code: item_code
 				}
+			}).then((r) => {
+				let serial_nos = r.message;
+				frm.set_query('serial_no', 'purposes', () => {
+					if (serial_nos.length > 0) {
+						return {
+							filters: {
+								'item_code': item_code,
+								'name': ["in", serial_nos]
+							}
+						};
+					}
+					return {
+						filters: {
+							'item_code': item_code
+						}
+					};
+				});
+			});
+		} else {
+			frm.set_query('serial_no', 'purposes', (frm, cdt, cdn) => {
+				let row = locals[cdt][cdn];
+				return {
+					filters: {
+						'item_code': row.item_code
+					}
+				};
 			});
 		}
 		if (!frm.doc.status) {
 			frm.set_value({ status: 'Draft' });
 		}
 		if (frm.doc.__islocal) {
-			frm.doc.maintenance_type == 'Unscheduled' && frm.clear_table("purposes");
 			frm.set_value({ mntc_date: frappe.datetime.get_today() });
 		}
 	},
@@ -60,7 +62,6 @@
 	contact_person: function (frm) {
 		erpnext.utils.get_contact_details(frm);
 	}
-
 })
 
 // TODO commonify this code
diff --git a/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.json b/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.json
index ec32239..4a6aa0a 100644
--- a/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.json
+++ b/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.json
@@ -179,8 +179,7 @@
    "label": "Purposes",
    "oldfieldname": "maintenance_visit_details",
    "oldfieldtype": "Table",
-   "options": "Maintenance Visit Purpose",
-   "reqd": 1
+   "options": "Maintenance Visit Purpose"
   },
   {
    "fieldname": "more_info",
@@ -294,10 +293,11 @@
  "idx": 1,
  "is_submittable": 1,
  "links": [],
- "modified": "2021-05-27 16:06:17.352572",
+ "modified": "2021-12-17 03:10:27.608112",
  "modified_by": "Administrator",
  "module": "Maintenance",
  "name": "Maintenance Visit",
+ "naming_rule": "By \"Naming Series\" field",
  "owner": "Administrator",
  "permissions": [
   {
diff --git a/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.py b/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.py
index 5a87b16..d5d8753 100644
--- a/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.py
+++ b/erpnext/maintenance/doctype/maintenance_visit/maintenance_visit.py
@@ -18,6 +18,10 @@
 			if d.serial_no and not frappe.db.exists("Serial No", d.serial_no):
 				frappe.throw(_("Serial No {0} does not exist").format(d.serial_no))
 
+	def validate_purpose_table(self):
+		if not self.purposes:
+			frappe.throw(_("Add Items in the Purpose Table"), title="Purposes Required")
+
 	def validate_maintenance_date(self):
 		if self.maintenance_type == "Scheduled" and self.maintenance_schedule_detail:
 			item_ref = frappe.db.get_value('Maintenance Schedule Detail', self.maintenance_schedule_detail, 'item_reference')
@@ -29,6 +33,7 @@
 	def validate(self):
 		self.validate_serial_no()
 		self.validate_maintenance_date()
+		self.validate_purpose_table()
 
 	def update_completion_status(self):
 		if self.maintenance_schedule_detail:
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index fa62b7f..1f83c4f 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -313,6 +313,7 @@
 erpnext.patches.v13_0.update_category_in_ltds_certificate
 erpnext.patches.v13_0.create_pan_field_for_india #2
 erpnext.patches.v14_0.delete_hub_doctypes
+erpnext.patches.v13_0.update_maintenance_schedule_field_in_visit
 erpnext.patches.v13_0.create_ksa_vat_custom_fields # 07-01-2022
 erpnext.patches.v14_0.rename_ongoing_status_in_sla_documents
 erpnext.patches.v14_0.migrate_crm_settings
diff --git a/erpnext/patches/v13_0/update_maintenance_schedule_field_in_visit.py b/erpnext/patches/v13_0/update_maintenance_schedule_field_in_visit.py
new file mode 100644
index 0000000..450c00e
--- /dev/null
+++ b/erpnext/patches/v13_0/update_maintenance_schedule_field_in_visit.py
@@ -0,0 +1,22 @@
+
+import frappe
+
+
+def execute():
+	# Updates the Maintenance Schedule link to fetch serial nos
+	from frappe.query_builder.functions import Coalesce
+	mvp = frappe.qb.DocType('Maintenance Visit Purpose')
+	mv = frappe.qb.DocType('Maintenance Visit')
+
+	frappe.qb.update(
+		mv
+	).join(
+		mvp
+	).on(mvp.parent == mv.name).set(
+		mv.maintenance_schedule,
+		Coalesce(mvp.prevdoc_docname, '')
+	).where(
+		(mv.maintenance_type == "Scheduled")
+		& (mvp.prevdoc_docname.notnull())
+		& (mv.docstatus < 2)
+	).run(as_dict=1)