diff --git a/erpnext/projects/doctype/dependent_task/__init__.py b/erpnext/projects/doctype/dependent_task/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/erpnext/projects/doctype/dependent_task/__init__.py
diff --git a/erpnext/projects/doctype/dependent_task/dependent_task.json b/erpnext/projects/doctype/dependent_task/dependent_task.json
new file mode 100644
index 0000000..c649b53
--- /dev/null
+++ b/erpnext/projects/doctype/dependent_task/dependent_task.json
@@ -0,0 +1,50 @@
+{
+ "allow_copy": 0, 
+ "allow_import": 0, 
+ "allow_rename": 0, 
+ "creation": "2015-04-29 04:52:48.868079", 
+ "custom": 0, 
+ "docstatus": 0, 
+ "doctype": "DocType", 
+ "document_type": "", 
+ "fields": [
+  {
+   "allow_on_submit": 0, 
+   "fieldname": "task", 
+   "fieldtype": "Link", 
+   "hidden": 0, 
+   "ignore_user_permissions": 0, 
+   "in_filter": 0, 
+   "in_list_view": 1, 
+   "label": "Task", 
+   "no_copy": 0, 
+   "options": "Task", 
+   "permlevel": 0, 
+   "precision": "", 
+   "print_hide": 0, 
+   "read_only": 0, 
+   "report_hide": 0, 
+   "reqd": 0, 
+   "search_index": 0, 
+   "set_only_once": 0
+  }
+ ], 
+ "hide_heading": 0, 
+ "hide_toolbar": 0, 
+ "in_create": 0, 
+ "in_dialog": 0, 
+ "is_submittable": 0, 
+ "issingle": 0, 
+ "istable": 1, 
+ "modified": "2015-04-29 04:54:36.024844", 
+ "modified_by": "Administrator", 
+ "module": "Projects", 
+ "name": "Dependent Task", 
+ "name_case": "", 
+ "owner": "Administrator", 
+ "permissions": [], 
+ "read_only": 0, 
+ "read_only_onload": 0, 
+ "sort_field": "modified", 
+ "sort_order": "DESC"
+}
\ No newline at end of file
diff --git a/erpnext/projects/doctype/dependent_task/dependent_task.py b/erpnext/projects/doctype/dependent_task/dependent_task.py
new file mode 100644
index 0000000..90a96ac
--- /dev/null
+++ b/erpnext/projects/doctype/dependent_task/dependent_task.py
@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors and contributors
+# For license information, please see license.txt
+
+from __future__ import unicode_literals
+import frappe
+from frappe.model.document import Document
+
+class DependentTask(Document):
+	pass
diff --git a/erpnext/projects/doctype/task/task.js b/erpnext/projects/doctype/task/task.js
index 9756331..d9a611e 100644
--- a/erpnext/projects/doctype/task/task.js
+++ b/erpnext/projects/doctype/task/task.js
@@ -40,6 +40,7 @@
 	}
 });
 
+cur_frm.add_fetch('task', 'subject', 'subject');
 
 cur_frm.cscript = new erpnext.projects.Task({frm: cur_frm});
 
diff --git a/erpnext/projects/doctype/task/task.json b/erpnext/projects/doctype/task/task.json
index fc604c2..ddcc48b 100644
--- a/erpnext/projects/doctype/task/task.json
+++ b/erpnext/projects/doctype/task/task.json
@@ -78,13 +78,27 @@
    "width": "300px"
   }, 
   {
-   "fieldname": "time_and_budget", 
+   "fieldname": "section_break", 
    "fieldtype": "Section Break", 
-   "label": "", 
+   "label": "Depends On", 
    "oldfieldtype": "Section Break", 
    "permlevel": 0
   }, 
   {
+   "fieldname": "depends_on", 
+   "fieldtype": "Table", 
+   "label": "depends_on", 
+   "options": "Task Depends On", 
+   "permlevel": 0, 
+   "precision": ""
+  }, 
+  {
+   "fieldname": "section_break_10", 
+   "fieldtype": "Section Break", 
+   "permlevel": 0, 
+   "precision": ""
+  }, 
+  {
    "fieldname": "exp_start_date", 
    "fieldtype": "Date", 
    "label": "Expected Start Date", 
@@ -249,7 +263,7 @@
  "idx": 1, 
  "istable": 0, 
  "max_attachments": 5, 
- "modified": "2015-04-14 07:56:24.481667", 
+ "modified": "2015-04-30 05:48:55.176993", 
  "modified_by": "Administrator", 
  "module": "Projects", 
  "name": "Task", 
diff --git a/erpnext/projects/doctype/task/task.py b/erpnext/projects/doctype/task/task.py
index a03340f..456c40a 100644
--- a/erpnext/projects/doctype/task/task.py
+++ b/erpnext/projects/doctype/task/task.py
@@ -4,12 +4,13 @@
 from __future__ import unicode_literals
 import frappe, json
 
-from frappe.utils import getdate
+from frappe.utils import getdate, date_diff, add_days, cstr
 from frappe import _
 
-
 from frappe.model.document import Document
 
+class CircularReferenceError(frappe.ValidationError): pass
+
 class Task(Document):
 	def get_feed(self):
 		return '{0}: {1}'.format(_(self.status), self.subject)
@@ -36,6 +37,8 @@
 			frappe.throw(_("'Actual Start Date' can not be greater than 'Actual End Date'"))
 
 	def on_update(self):
+		self.check_recursion()
+		self.reschedule_dependent_tasks()
 		self.update_percentage()
 		self.update_project()
 			
@@ -52,8 +55,8 @@
 	def update_time_and_costing(self):
 		tl = frappe.db.sql("""select min(from_time) as start_date, max(to_time) as end_date,
 			 sum(billing_amount) as total_billing_amount, sum(costing_amount) as total_costing_amount,
-			sum(hours) as time from `tabTime Log` where project = %s and task = %s and docstatus=1""",
-			(self.project, self.name),as_dict=1)[0]
+			sum(hours) as time from `tabTime Log` where task = %s and docstatus=1"""
+			,self.name, as_dict=1)[0]
 		if self.status == "Open":
 			self.status = "Working"
 		self.total_costing_amount= tl.total_costing_amount
@@ -68,6 +71,36 @@
 			project.flags.dont_sync_tasks = True
 			project.update_costing()
 			project.save()
+			
+	def check_recursion(self):
+		if self.flags.ignore_recursion_check: return
+		check_list = [['task', 'parent'], ['parent', 'task']]
+		for d in check_list:
+			task_list, count = [self.name], 0
+			while (len(task_list) > count ):
+				tasks = frappe.db.sql(" select %s from `tabTask Depends On` where %s = %s " %
+					(d[0], d[1], '%s'), cstr(task_list[count]))
+				count = count + 1
+				for b in tasks:
+					if b[0] == self.name:
+						frappe.throw(_("Circular Reference Error"), CircularReferenceError)
+					if b[0]:
+						task_list.append(b[0])
+				if count == 15:
+					break
+			
+	def reschedule_dependent_tasks(self):
+		end_date = self.exp_end_date or self.act_end_date
+		if end_date:
+			for task_name in frappe.db.sql("select name from `tabTask` as parent where %s in \
+				(select task from `tabTask Depends On` as child where parent.name = child.parent )", self.name, as_dict=1):
+				task = frappe.get_doc("Task", task_name.name)
+				if task.exp_start_date and task.exp_end_date and task.exp_start_date < getdate(end_date) and task.status == "Open" :
+					task_duration = date_diff(task.exp_end_date, task.exp_start_date)
+					task.exp_start_date = add_days(end_date, 1)
+					task.exp_end_date = add_days(task.exp_start_date, task_duration)
+					task.flags.ignore_recursion_check = True
+					task.save()
 
 @frappe.whitelist()
 def get_events(start, end, filters=None):
diff --git a/erpnext/projects/doctype/task/test_task.py b/erpnext/projects/doctype/task/test_task.py
index 62e560f..8880763 100644
--- a/erpnext/projects/doctype/task/test_task.py
+++ b/erpnext/projects/doctype/task/test_task.py
@@ -1,7 +1,148 @@
 # Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
 # License: GNU General Public License v3. See license.txt
 from __future__ import unicode_literals
-
-
 import frappe
-test_records = frappe.get_test_records('Task')
+import unittest
+from frappe.utils import getdate
+
+# test_records = frappe.get_test_records('Task')
+
+from erpnext.projects.doctype.task.task import CircularReferenceError
+
+class TestTask(unittest.TestCase):
+	def test_circular_reference(self):
+		
+		task1 =  frappe.new_doc('Task')
+		task1.update({
+			"status": "Open", 
+			"subject": "_Test Task 1",
+			"exp_start_date": "2015-1-1",
+			"exp_end_date": "2015-1-10"
+		})
+		task1.save()
+		
+		task2 =  frappe.new_doc('Task')
+		task2.update({
+			"status": "Open", 
+			"subject": "_Test Task 2",
+			"exp_start_date": "2015-1-11",
+			"exp_end_date": "2015-1-15",
+			"depends_on":[
+				{
+					"task": task1.name
+				}
+			]
+		})
+		task2.save()
+		
+		task3 =  frappe.new_doc('Task')
+		task3.update({
+			"status": "Open", 
+			"subject": "_Test Task 2",
+			"exp_start_date": "2015-1-11",
+			"exp_end_date": "2015-1-15",
+			"depends_on":[
+				{
+					"task": task2.name
+				}
+			]
+		})
+		task3.save()
+
+		task1.append("depends_on", {
+			"task": task3.name
+		})
+		self.assertRaises(CircularReferenceError, task1.save)
+		
+		task1.set("depends_on", [])
+		task1.save()
+		
+		task4 =  frappe.new_doc('Task')
+		task4.update({
+			"status": "Open", 
+			"subject": "_Test Task 1",
+			"exp_start_date": "2015-1-1",
+			"exp_end_date": "2015-1-15",
+			"depends_on":[
+				{
+					"task": task1.name
+				}
+			]
+		})
+		task4.save()
+
+		task3.append("depends_on", {
+			"task": task4.name
+		})
+		
+	def test_reschedule_dependent_task(self):
+		task1 =  frappe.new_doc('Task')
+		task1.update({
+			"status": "Open", 
+			"subject": "_Test Task 1",
+			"exp_start_date": "2015-1-1",
+			"exp_end_date": "2015-1-10"
+		})
+		task1.save()
+		
+		task2 =  frappe.new_doc('Task')
+		task2.update({
+			"status": "Open", 
+			"subject": "_Test Task 2",
+			"exp_start_date": "2015-1-11",
+			"exp_end_date": "2015-1-15",
+			"depends_on":[
+				{
+					"task": task1.name
+				}
+			]
+		})
+		task2.save()
+		
+		task3 =  frappe.new_doc('Task')
+		task3.update({
+			"status": "Open", 
+			"subject": "_Test Task 3",
+			"exp_start_date": "2015-1-16",
+			"exp_end_date": "2015-1-18",
+			"depends_on":[
+				{
+					"task": task2.name
+				}
+			]
+		})
+		task3.save()
+		
+		task1.update({
+			"exp_end_date": "2015-1-20"
+		})
+		task1.save()
+		
+		self.assertEqual(frappe.db.get_value("Task", task2.name, "exp_start_date"), getdate('2015-1-21'))
+		self.assertEqual(frappe.db.get_value("Task", task2.name, "exp_end_date"), getdate('2015-1-25'))
+
+		self.assertEqual(frappe.db.get_value("Task", task3.name, "exp_start_date"), getdate('2015-1-26'))
+		self.assertEqual(frappe.db.get_value("Task", task3.name, "exp_end_date"), getdate('2015-1-28'))
+		
+		time_log = frappe.new_doc('Time Log')
+		time_log.update({
+			"from_time": "2015-1-1",
+			"to_time": "2015-1-20",
+			"task": task1.name
+		})
+		time_log.submit()
+		
+		self.assertEqual(frappe.db.get_value("Task", task2.name, "exp_start_date"), getdate('2015-1-21'))
+		self.assertEqual(frappe.db.get_value("Task", task2.name, "exp_end_date"), getdate('2015-1-25'))
+
+		self.assertEqual(frappe.db.get_value("Task", task3.name, "exp_start_date"), getdate('2015-1-26'))
+		self.assertEqual(frappe.db.get_value("Task", task3.name, "exp_end_date"), getdate('2015-1-28'))
+		
+		time_log.cancel()
+		
+		self.assertEqual(frappe.db.get_value("Task", task2.name, "exp_start_date"), getdate('2015-1-21'))
+		self.assertEqual(frappe.db.get_value("Task", task2.name, "exp_end_date"), getdate('2015-1-25'))
+
+		self.assertEqual(frappe.db.get_value("Task", task3.name, "exp_start_date"), getdate('2015-1-26'))
+		self.assertEqual(frappe.db.get_value("Task", task3.name, "exp_end_date"), getdate('2015-1-28'))
+		
\ No newline at end of file
diff --git a/erpnext/projects/doctype/task_depends_on/__init__.py b/erpnext/projects/doctype/task_depends_on/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/erpnext/projects/doctype/task_depends_on/__init__.py
diff --git a/erpnext/projects/doctype/task_depends_on/task_depends_on.json b/erpnext/projects/doctype/task_depends_on/task_depends_on.json
new file mode 100644
index 0000000..7a960c1
--- /dev/null
+++ b/erpnext/projects/doctype/task_depends_on/task_depends_on.json
@@ -0,0 +1,66 @@
+{
+ "allow_copy": 0, 
+ "allow_import": 0, 
+ "allow_rename": 0, 
+ "creation": "2015-04-29 04:52:48.868079", 
+ "custom": 0, 
+ "docstatus": 0, 
+ "doctype": "DocType", 
+ "document_type": "", 
+ "fields": [
+  {
+   "allow_on_submit": 0, 
+   "fieldname": "task", 
+   "fieldtype": "Link", 
+   "hidden": 0, 
+   "ignore_user_permissions": 0, 
+   "in_filter": 0, 
+   "in_list_view": 1, 
+   "label": "Task", 
+   "no_copy": 0, 
+   "options": "Task", 
+   "permlevel": 0, 
+   "precision": "", 
+   "print_hide": 0, 
+   "read_only": 0, 
+   "report_hide": 0, 
+   "reqd": 0, 
+   "search_index": 0, 
+   "set_only_once": 0
+  }, 
+  {
+   "fieldname": "column_break_2", 
+   "fieldtype": "Column Break", 
+   "permlevel": 0, 
+   "precision": ""
+  }, 
+  {
+   "fieldname": "subject", 
+   "fieldtype": "Text", 
+   "in_list_view": 1, 
+   "label": "Subject", 
+   "options": "", 
+   "permlevel": 0, 
+   "precision": "", 
+   "read_only": 1
+  }
+ ], 
+ "hide_heading": 0, 
+ "hide_toolbar": 0, 
+ "in_create": 0, 
+ "in_dialog": 0, 
+ "is_submittable": 0, 
+ "issingle": 0, 
+ "istable": 1, 
+ "modified": "2015-04-30 05:52:16.250948", 
+ "modified_by": "Administrator", 
+ "module": "Projects", 
+ "name": "Task Depends On", 
+ "name_case": "", 
+ "owner": "Administrator", 
+ "permissions": [], 
+ "read_only": 0, 
+ "read_only_onload": 0, 
+ "sort_field": "modified", 
+ "sort_order": "DESC"
+}
\ No newline at end of file
diff --git a/erpnext/projects/doctype/task_depends_on/task_depends_on.py b/erpnext/projects/doctype/task_depends_on/task_depends_on.py
new file mode 100644
index 0000000..723a0fc
--- /dev/null
+++ b/erpnext/projects/doctype/task_depends_on/task_depends_on.py
@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors and contributors
+# For license information, please see license.txt
+
+from __future__ import unicode_literals
+import frappe
+from frappe.model.document import Document
+
+class TaskDependsOn(Document):
+	pass
diff --git a/erpnext/projects/doctype/time_log/test_time_log.py b/erpnext/projects/doctype/time_log/test_time_log.py
index 3d9e0be..9b43b0d 100644
--- a/erpnext/projects/doctype/time_log/test_time_log.py
+++ b/erpnext/projects/doctype/time_log/test_time_log.py
@@ -1,6 +1,5 @@
 # Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
 # License: GNU General Public License v3. See license.txt
-from __future__ import unicode_literals
 
 from __future__ import unicode_literals
 import frappe