diff --git a/dvc/git_wrapper.py b/dvc/git_wrapper.py
index 1e77a48b9..754a317bc 100644
--- a/dvc/git_wrapper.py
+++ b/dvc/git_wrapper.py
@@ -4,7 +4,7 @@ from dvc.logger import Logger
 from dvc.config import Config
 from dvc.executor import Executor, ExecutorError
 from dvc.system import System
-from dvc.workflow import Workflow
+from dvc.workflow import Workflow, Commit
 
 
 class GitWrapperI(object):
@@ -248,8 +248,8 @@ class GitWrapper(GitWrapperI):
                 assert len(items) == 5, 'Git wrapper: git log format has {} items, 5 expected'.format(len(items))
                 hash, parent_hash, name, date, comment = items
 
-                wf.add_commit(hash, parent_hash, name, date, comment,
-                              GitWrapper.is_target(hash, target))
+                wf.add_commit(Commit(hash, parent_hash, name, date, comment,
+                              GitWrapper.is_target(hash, target)))
 
             return wf
         except ExecutorError:
diff --git a/dvc/workflow.py b/dvc/workflow.py
index 2e18f6429..349fd34d7 100644
--- a/dvc/workflow.py
+++ b/dvc/workflow.py
@@ -9,76 +9,97 @@ class WorkflowError(DvcException):
 
 
 class Commit(object):
-    def __init__(self, hash, parent_hash, name, date, comment, is_target):
+    TEXT_LIMIT = 30
+    DVC_REPRO_PREFIX = 'DVC repro'
+    COLLAPSED_TEXT = DVC_REPRO_PREFIX + '\n<< collapsed commits >>'
+
+    def __init__(self, hash, parents, name, date, comment, is_target):
         self._hash = hash
-        self._parent_hash = parent_hash
+        self._parent_hashes = set(parents.split())
         self._name = name
         self._date = date
         self._comment = comment
         self._is_target = is_target
+        self._is_collapsed = False
 
     @property
     def hash(self):
         return self._hash
 
+    @property
+    def parent_hashes(self):
+        return self._parent_hashes
+
+    def add_parents(self, parent_hashes):
+        self._parent_hashes |= parent_hashes
+
+    def remove_parent(self, hash):
+        self._parent_hashes.remove(hash)
+
+    @property
+    def text(self):
+        if self._is_collapsed:
+            return self.COLLAPSED_TEXT
+        return self._comment[:self.TEXT_LIMIT] + '\n' + self.hash
+
+    @property
+    def is_repro(self):
+        return self._comment.startswith(self.DVC_REPRO_PREFIX)
+
+    def make_colapsed(self):
+        self._is_collapsed = True
+
 
 class Workflow(object):
-    '''
-    Options:
-    --all   -   all commits
-    //--no-repro - by default (no DVC commits)
-    --no-dvc    - no DVC commits
-    
-    '''
-
-    COMMIT_TEXT_LIMIT = 20
-
-    def __init__(self, target, merges_map):
+    def __init__(self, target, merges_map, root='', no_repro_commits=True):
         self._target = target
         self._merges_map = merges_map
 
         self._commits = {}
-        self._root = {}
+        self._root = root
+
+        self._edges = {}
+        self._back_edges = {}
+
+        self._no_repro_commits = no_repro_commits
         pass
 
-    def add_commit(self, hash, parent_hash, name, date, comment, is_target):
-        # Extract params to the Commit class?
-        print 'add_commit %s' % (hash)
-        self._commits[hash] = Commit(hash, parent_hash, name, date, comment, is_target)
-        if not parent_hash:
-            self._root = hash
+    def add_commit(self, commit):
+        self._commits[commit.hash] = commit
+
+        for p in commit.parent_hashes:
+            if p not in self._edges:
+                self._edges[p] = set()
+            self._edges[p].add(commit.hash)
+
+        if commit.hash not in self._back_edges:
+            self._back_edges[commit.hash] = set()
+        for p in commit.parent_hashes:
+            self._back_edges[commit.hash].add(p)
         pass
 
     def build_graph(self):
         g = nx.DiGraph(name='DVC Workflow', directed=False)
 
-        if not self._root:
-            raise WorkflowError('cannot find root commit')
+        if self._no_repro_commits:
+            self.collaps_repro_commits()
+
+        for hash in set(self._edges.keys() + self._back_edges.keys()):
+            commit = self._commits[hash]
+            g.add_node(hash,
+                       attr_dict={
+                           'label': commit.text,
+                           'color': 'red' if commit.hash == '85d03b2' else 'black',
+                           'weight': 8 if commit.hash == '411ea7c' else 18
+                       }
+            )
 
-        # self._build_graph(self._commits[self._root], g)
-        visited = set()
         for commit in self._commits.values():
-            if commit.hash not in visited:
-                g.add_node(commit.hash,
-                           attr_dict={
-                               'label': commit._comment[:Workflow.COMMIT_TEXT_LIMIT] + '\n' + commit.hash,
-                                'color': 'red' if commit.hash == '85d03b2' else 'black',
-                                'weight': 8 if commit.hash == '411ea7c' else 18
-                           }
-                )
-                visited.add(commit.hash)
-            if commit._parent_hash:
-                g.add_edge(commit.hash, commit._parent_hash)
-                if commit.hash == '411ea7c':
-                    g.add_edge(commit.hash, commit._parent_hash, attr_dict={
-                        'color': 'green'
-                    })
-                    g.add_edge(commit.hash, commit._parent_hash, attr_dict={
-                        'color': 'red'
-                    })
+            for p in commit.parent_hashes:
+                g.add_edge(commit.hash, p)
 
         A = nx.nx_agraph.to_agraph(g)
-        fname = 'workflow'
+        fname = 'workflow.jpeg'
         A = A.to_undirected()
         A.write(fname + '.dot')
         A.draw(fname, format='jpeg', prog='dot')
@@ -89,9 +110,39 @@ class Workflow(object):
             return
         next = self._commits[curr.hash]
 
-        print 'add node %s' % next.hash
         g.add_node(next.hash)
-        print 'add edge (%s, %s)' % (curr.hash, next.hash)
         g.add_edge(curr.hash, next.hash)
 
         self._build_graph(next, g)
+
+    def collaps_repro_commits(self):
+        hashes_to_remove = []
+        for commit in self._commits.values():
+            if commit.is_repro:
+                parent_commit_hashes = self._back_edges[commit.hash]
+                child_commit_hashes = self._edges.get(commit.hash)
+
+                # Remove if next commit is dvc-repro as well
+                if child_commit_hashes and all(self._commits[hash].is_repro for hash in child_commit_hashes):
+                    for hash in child_commit_hashes:
+                        self._commits[hash].add_parents(commit.parent_hashes)
+                        self._commits[hash].remove_parent(commit.hash)
+                        pass
+
+                    for hash in parent_commit_hashes:
+                        self._edges[hash].remove(commit.hash)
+                        self._edges[hash] |= child_commit_hashes
+
+                    for hash in child_commit_hashes:
+                        self._back_edges[hash].remove(commit.hash)
+                        self._back_edges[hash] |= parent_commit_hashes
+
+                    hashes_to_remove.append(commit.hash)
+                else:
+                    commit.make_colapsed()
+
+        for hash in hashes_to_remove:
+            del self._commits[hash]
+            del self._edges[hash]
+            del self._back_edges[hash]
+        pass
diff --git a/functest/requirements.txt b/functest/requirements.txt
index 22924891c..80a128f8e 100644
--- a/functest/requirements.txt
+++ b/functest/requirements.txt
@@ -2,3 +2,5 @@ dvc
 pandas
 sklearn
 scipy
+configobj
+networkx
diff --git a/functest/tutorial_branches.sh b/functest/tutorial_branches.sh
index 1a954760a..249e82a6a 100755
--- a/functest/tutorial_branches.sh
+++ b/functest/tutorial_branches.sh
@@ -6,6 +6,13 @@ set -e
 
 mkdir myrepo
 cd myrepo
+
+git init
+echo "This is an empty readme" > README.md
+git add README.md
+git commit -m 'add readme'
+
+git checkout -b first_model
 mkdir code
 wget -nv -P code/ https://s3-us-west-2.amazonaws.com/dvc-share/so/code/featurization.py \
         https://s3-us-west-2.amazonaws.com/dvc-share/so/code/evaluate.py \
@@ -13,15 +20,14 @@ wget -nv -P code/ https://s3-us-west-2.amazonaws.com/dvc-share/so/code/featuriza
         https://s3-us-west-2.amazonaws.com/dvc-share/so/code/split_train_test.py \
         https://s3-us-west-2.amazonaws.com/dvc-share/so/code/xml_to_tsv.py \
         https://s3-us-west-2.amazonaws.com/dvc-share/so/code/requirements.txt
-pip install -U -r code/requirements.txt
-
-git init
+#pip install -U -r code/requirements.txt
+# Edit eval file format
 git add code/
 git commit -m 'Download code'
 
 
 dvc init
-dvc import https://s3-us-west-2.amazonaws.com/dvc-share/so/10K/Posts.xml.tgz data/
+dvc import https://s3-us-west-2.amazonaws.com/dvc-share/so/100K/Posts.xml.tgz data/
 dvc run tar zxf data/Posts.xml.tgz -C data/
 
 dvc run python code/xml_to_tsv.py data/Posts.xml data/Posts.tsv python
@@ -34,17 +40,9 @@ dvc run python code/evaluate.py data/model.p data/matrix-test.p data/eval_auc.tx
 
 dvc target data/eval_auc.txt
 cat data/eval_auc.txt
-# AUC: 0.349
+# AUC: 0.645320
 
 
-git checkout -b input_100K  #  <--
-dvc remove data/Posts.xml.tgz
-dvc import https://s3-us-west-2.amazonaws.com/dvc-share/so/100K/Posts.xml.tgz data/
-dvc repro
-cat data/eval_auc.txt
-# 0.645320
-
-git checkout master     # <--
 git checkout -b input_25K # <--
 dvc remove data/Posts.xml.tgz
 dvc import https://s3-us-west-2.amazonaws.com/dvc-share/so/25K/Posts.xml.tgz data/
@@ -73,16 +71,21 @@ cat data/eval_auc.txt
 # 0.621002
 
 git checkout 2195f1032 -b three_grams # <--
+dvc repro # not needed
+cat data/eval_auc.txt
+# 0.630682
+
+git checkout first_model
+git merge three_grams
+dvc repro
+
+
+
 vi code/featurization.py
 # 0.578447
 
 
 
-
-
-
-
-
 # 2. Reproduce: change input dataset
 
 dvc remove data/Posts.xml.tgz
diff --git a/tests/test_workflow.py b/tests/test_workflow.py
new file mode 100644
index 000000000..db9211f36
--- /dev/null
+++ b/tests/test_workflow.py
@@ -0,0 +1,66 @@
+from unittest import TestCase
+
+from dvc.workflow import Workflow, Commit
+
+
+class TestWorkflow(TestCase):
+    def setUp(self):
+        self._commit4 = Commit('4', '3', 'name1', 'today', 'comment4', False)
+        self._commit3 = Commit('3', '2', 'name1', 'today', 'DVC repro-run ...', False)
+        self._commit2 = Commit('2', '1', 'name1', 'today', 'DVC repro-run ...', False)
+        self._commit1 = Commit('1', '', 'name1', 'today', 'comment1', False)
+
+    def test_commits(self):
+        self.assertFalse(self._commit1.is_repro)
+        self.assertTrue(self._commit2.is_repro)
+        self.assertTrue(self._commit3.is_repro)
+        self.assertFalse(self._commit4.is_repro)
+        pass
+
+    def test_workflow_basic(self):
+        wf = Workflow('', '')
+        wf.add_commit(self._commit1)
+        wf.add_commit(self._commit2)
+        wf.add_commit(self._commit3)
+        wf.add_commit(self._commit4)
+
+        self.assertEqual(len(wf._commits), 4)
+
+        self.assertEqual(wf._commits['1'].text, self._commit1._comment + '\n' + self._commit1.hash)
+        self.assertEqual(wf._commits['2'].text, self._commit2._comment + '\n' + self._commit2.hash)
+        self.assertEqual(wf._commits['3'].text, self._commit3._comment + '\n' + self._commit3.hash)
+        self.assertEqual(wf._commits['4'].text, self._commit4._comment + '\n' + self._commit4.hash)
+        pass
+
+    def test_collapse(self):
+        wf = Workflow('', '')
+        wf.add_commit(self._commit1)
+        wf.add_commit(self._commit2)
+        wf.add_commit(self._commit3)
+        wf.add_commit(self._commit4)
+
+        wf.collaps_repro_commits()
+
+        self.assertEqual(len(wf._commits), 3)
+        self.assertEqual(wf._commits[self._commit1.hash].text, self._commit1._comment + '\n' + self._commit1.hash)
+        self.assertEqual(wf._commits[self._commit3.hash].text, Commit.COLLAPSED_TEXT)
+        self.assertTrue('2' not in wf._commits)
+
+        self.assertFalse('2' in wf._edges)
+        self.assertFalse('2' in wf._back_edges)
+        pass
+
+    def test_collapse_at_dead_end(self):
+        wf = Workflow('', '')
+        wf.add_commit(self._commit1)
+        wf.add_commit(self._commit2)
+        wf.add_commit(self._commit3) # Dead end which cannot be collapsed
+
+        self.assertEqual(len(wf._commits), 3)
+        wf.collaps_repro_commits()
+        self.assertEqual(len(wf._commits), 2)
+
+        self.assertEqual(wf._commits[self._commit1.hash].text, self._commit1._comment + '\n' + self._commit1.hash)
+        self.assertEqual(wf._commits[self._commit3.hash].text, Commit.COLLAPSED_TEXT)
+        self.assertTrue('2' not in wf._commits)
+        pass