diff --git a/erpnext/manufacturing/doctype/job_card/job_card.js b/erpnext/manufacturing/doctype/job_card/job_card.js
index 6469fada2ba..af6b3c3da37 100644
--- a/erpnext/manufacturing/doctype/job_card/job_card.js
+++ b/erpnext/manufacturing/doctype/job_card/job_card.js
@@ -199,7 +199,10 @@ frappe.ui.form.on("Job Card", {
 				last_row = get_last_row(frm.doc.time_logs);
 			}
 
-			if (!frm.doc.time_logs?.length || (frm.doc.sub_operations?.length && last_row?.to_time)) {
+			if (
+				(!frm.doc.time_logs?.length || (frm.doc.sub_operations?.length && last_row?.to_time)) &&
+				!frm.doc.is_paused
+			) {
 				frm.add_custom_button(__("Start Job"), () => {
 					let from_time = frappe.datetime.now_datetime();
 					if ((frm.doc.employee && !frm.doc.employee.length) || !frm.doc.employee) {
@@ -327,6 +330,26 @@ frappe.ui.form.on("Job Card", {
 			},
 		];
 
+		if (frm.doc.sub_operations?.length) {
+			fields.push({
+				fieldtype: "Link",
+				label: __("Sub Operation"),
+				fieldname: "sub_operation",
+				options: "Operation",
+				get_query() {
+					let non_completed_operations = frm.doc.sub_operations.filter(
+						(d) => d.status === "Pending"
+					);
+					return {
+						filters: {
+							name: ["in", non_completed_operations.map((d) => d.sub_operation)],
+						},
+					};
+				},
+				reqd: 1,
+			});
+		}
+
 		let last_completed_row = get_last_completed_row(frm.doc.time_logs);
 		let last_row = {};
 		if (frm.doc.sub_operations?.length && frm.doc.time_logs?.length) {
@@ -356,6 +379,7 @@ frappe.ui.form.on("Job Card", {
 						qty: data.completed_qty,
 						for_quantity: data.for_quantity,
 						end_time: data.end_time,
+						sub_operation: data.sub_operation,
 					},
 					callback: function (r) {
 						frm.reload_doc();
diff --git a/erpnext/manufacturing/doctype/job_card/job_card.py b/erpnext/manufacturing/doctype/job_card/job_card.py
index 3de30c38881..367548864c3 100644
--- a/erpnext/manufacturing/doctype/job_card/job_card.py
+++ b/erpnext/manufacturing/doctype/job_card/job_card.py
@@ -643,7 +643,7 @@ class JobCard(Document):
 			op_row.employee.append(time_log.employee)
 			if time_log.time_in_mins:
 				op_row.completed_time += time_log.time_in_mins
-				op_row.completed_qty += time_log.completed_qty
+				op_row.completed_qty += flt(time_log.completed_qty)
 
 		for row in self.sub_operations:
 			operation_deatils = operation_wise_completed_time.get(row.sub_operation)
@@ -1224,6 +1224,8 @@ class JobCard(Document):
 
 					row.to_time = kwargs.to_time
 					row.time_in_mins = time_diff_in_minutes(row.to_time, row.from_time)
+					if kwargs.get("sub_operation"):
+						row.operation = kwargs.get("sub_operation")
 
 					if kwargs.employees[-1].get("employee") == row.employee:
 						row.completed_qty = kwargs.completed_qty
@@ -1276,7 +1278,12 @@ class JobCard(Document):
 			kwargs = frappe._dict(kwargs)
 
 		if kwargs.end_time:
-			self.add_time_logs(to_time=kwargs.end_time, completed_qty=kwargs.qty, employees=self.employee)
+			self.add_time_logs(
+				to_time=kwargs.end_time,
+				completed_qty=kwargs.qty,
+				employees=self.employee,
+				sub_operation=kwargs.get("sub_operation"),
+			)
 
 			if kwargs.for_quantity:
 				self.for_quantity = kwargs.for_quantity