diff --git a/taskflow/examples/run_by_iter.out.txt b/taskflow/examples/run_by_iter.out.txt
new file mode 100644
index 00000000..6e12eb40
--- /dev/null
+++ b/taskflow/examples/run_by_iter.out.txt
@@ -0,0 +1,106 @@
+RESUMING
+SCHEDULING
+A
+WAITING
+ANALYZING
+SCHEDULING
+B
+WAITING
+ANALYZING
+SCHEDULING
+C
+WAITING
+ANALYZING
+SCHEDULING
+D
+WAITING
+ANALYZING
+SCHEDULING
+E
+WAITING
+ANALYZING
+SCHEDULING
+F
+WAITING
+ANALYZING
+SCHEDULING
+G
+WAITING
+ANALYZING
+SCHEDULING
+H
+WAITING
+ANALYZING
+SCHEDULING
+I
+WAITING
+ANALYZING
+SCHEDULING
+J
+WAITING
+ANALYZING
+SCHEDULING
+K
+WAITING
+ANALYZING
+SCHEDULING
+L
+WAITING
+ANALYZING
+SCHEDULING
+M
+WAITING
+ANALYZING
+SCHEDULING
+N
+WAITING
+ANALYZING
+SCHEDULING
+O
+WAITING
+ANALYZING
+SCHEDULING
+P
+WAITING
+ANALYZING
+SCHEDULING
+Q
+WAITING
+ANALYZING
+SCHEDULING
+R
+WAITING
+ANALYZING
+SCHEDULING
+S
+WAITING
+ANALYZING
+SCHEDULING
+T
+WAITING
+ANALYZING
+SCHEDULING
+U
+WAITING
+ANALYZING
+SCHEDULING
+V
+WAITING
+ANALYZING
+SCHEDULING
+W
+WAITING
+ANALYZING
+SCHEDULING
+X
+WAITING
+ANALYZING
+SCHEDULING
+Y
+WAITING
+ANALYZING
+SCHEDULING
+Z
+WAITING
+ANALYZING
+SUCCESS
diff --git a/taskflow/examples/run_by_iter.py b/taskflow/examples/run_by_iter.py
new file mode 100644
index 00000000..0a7761b7
--- /dev/null
+++ b/taskflow/examples/run_by_iter.py
@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+
+#    Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import logging
+import os
+import sys
+
+import six
+
+logging.basicConfig(level=logging.ERROR)
+
+self_dir = os.path.abspath(os.path.dirname(__file__))
+top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__),
+                                       os.pardir,
+                                       os.pardir))
+sys.path.insert(0, top_dir)
+sys.path.insert(0, self_dir)
+
+
+from taskflow.engines.action_engine import engine
+from taskflow.patterns import linear_flow as lf
+from taskflow.persistence.backends import impl_memory
+from taskflow import task
+from taskflow.utils import persistence_utils
+
+
+# INTRO: This examples shows how to run a set of engines at the same time, each
+# running in different engines using a single thread of control to iterate over
+# each engine (which causes that engine to advanced to its next state during
+# each iteration).
+
+
+class EchoTask(task.Task):
+    def execute(self, value):
+        print(value)
+        return chr(ord(value) + 1)
+
+
+def make_alphabet_flow(i):
+    f = lf.Flow("alphabet_%s" % (i))
+    start_value = 'A'
+    end_value = 'Z'
+    curr_value = start_value
+    while ord(curr_value) <= ord(end_value):
+        next_value = chr(ord(curr_value) + 1)
+        if curr_value != end_value:
+            f.add(EchoTask(name="echoer_%s" % curr_value,
+                           rebind={'value': curr_value},
+                           provides=next_value))
+        else:
+            f.add(EchoTask(name="echoer_%s" % curr_value,
+                           rebind={'value': curr_value}))
+        curr_value = next_value
+    return f
+
+
+# Adjust this number to change how many engines/flows run at once.
+flow_count = 1
+flows = []
+for i in range(0, flow_count):
+    f = make_alphabet_flow(i + 1)
+    flows.append(make_alphabet_flow(i + 1))
+be = impl_memory.MemoryBackend({})
+book = persistence_utils.temporary_log_book(be)
+engines = []
+for f in flows:
+    fd = persistence_utils.create_flow_detail(f, book, be)
+    e = engine.SingleThreadedActionEngine(f, fd, be, {})
+    e.compile()
+    e.storage.inject({'A': 'A'})
+    e.prepare()
+    engines.append(e)
+engine_iters = []
+for e in engines:
+    engine_iters.append(e.run_iter())
+while engine_iters:
+    for it in list(engine_iters):
+        try:
+            print(six.next(it))
+        except StopIteration:
+            engine_iters.remove(it)