diff --git a/mistral/db/sqlalchemy/models.py b/mistral/db/sqlalchemy/models.py
index 48ac3ffd5..49b681439 100644
--- a/mistral/db/sqlalchemy/models.py
+++ b/mistral/db/sqlalchemy/models.py
@@ -91,8 +91,8 @@ class Task(mb.MistralBase):
     workbook_name = sa.Column(sa.String(80))
     execution_id = sa.Column(sa.String(36))
     description = sa.Column(sa.String())
-    task_dsl = sa.Column(st.JsonDictType())
-    service_dsl = sa.Column(st.JsonDictType())
+    task_spec = sa.Column(st.JsonDictType())
+    service_spec = sa.Column(st.JsonDictType())
     state = sa.Column(sa.String(20))
     tags = sa.Column(st.JsonListType())
 
diff --git a/mistral/dsl.py b/mistral/dsl.py
deleted file mode 100644
index 421df1354..000000000
--- a/mistral/dsl.py
+++ /dev/null
@@ -1,116 +0,0 @@
-# -*- coding: utf-8 -*-
-#
-# Copyright 2013 - Mirantis, Inc.
-#
-#    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 yaml
-from yaml import error
-
-
-class Parser(object):
-    """Mistral DSL parser.
-
-    Loads a workbook definition in YAML format as described in Mistral DSL
-    specification and provides various methods to access DSL entities like
-    tasks and actions in a form of dictionary.
-    """
-    def __init__(self, workbook_definition):
-        try:
-            self.doc = yaml.safe_load(workbook_definition)
-        except error.YAMLError as exc:
-            raise RuntimeError("Definition could not be parsed: %s\n" % exc)
-
-    def get_services(self):
-        services = []
-        for service_name in self.doc.get("Services", []):
-            services.append(self.doc["Services"][service_name])
-        return services
-
-    def get_service(self, service_name):
-        return self.doc["Services"].get(service_name, {})
-
-    def get_events(self):
-        events_from_doc = self.doc["Workflow"].get("events", None)
-        if not events_from_doc:
-            return []
-        events = []
-        for name in events_from_doc:
-            event_dict = {'name': name}
-            event_dict.update(events_from_doc[name])
-            events.append(event_dict)
-        return events
-
-    def get_tasks(self):
-        tasks = self.doc.get("Workflow", {}).get("tasks", {})
-
-        for _, task_dsl in tasks.iteritems():
-            task_dsl["service_name"] = task_dsl["action"].split(':')[0]
-            req = task_dsl.get("requires")
-            if req and isinstance(req, list):
-                task_dsl["requires"] = dict(zip(req, ['']*len(req)))
-
-        return tasks
-
-    def get_task(self, task_name):
-        task = self.get_tasks().get(task_name, {})
-        if task:
-            task['name'] = task_name
-        return task
-
-    def get_task_dsl_property(self, task_name, property_name):
-        task_dsl = self.get_task(task_name)
-        return task_dsl.get(property_name)
-
-    def get_task_on_error(self, task_name):
-        task = self.get_task_dsl_property(task_name, "on-error")
-        if task:
-            return task if isinstance(task, dict) else {task: ''}
-        return None
-
-    def get_task_on_success(self, task_name):
-        task = self.get_task_dsl_property(task_name, "on-success")
-        if task:
-            return task if isinstance(task, dict) else {task: ''}
-        return None
-
-    def get_task_on_finish(self, task_name):
-        task = self.get_task_dsl_property(task_name, "on-finish")
-        if task:
-            return task if isinstance(task, dict) else {task: ''}
-        return None
-
-    def get_task_input(self, task_name):
-        return self.get_task_dsl_property(task_name, "input")
-
-    def get_action(self, task_action_name):
-        if task_action_name.find(":") == -1:
-            return {}
-        service_name = task_action_name.split(':')[0]
-        action_name = task_action_name.split(':')[1]
-        action = self.get_service(service_name)['actions'][action_name]
-        return action
-
-    def get_actions(self, service_name):
-        service = self.get_service(service_name)
-        return service.get('actions', [])
-
-    def get_service_names(self):
-        names = []
-        for name in self.doc['Services']:
-            names.append(name)
-        return names
-
-    def get_event_task_name(self, event_name):
-        event = self.doc["Workflow"]["events"].get(event_name)
-        return event.get('tasks') if event else ""
diff --git a/mistral/dsl_parser.py b/mistral/dsl_parser.py
new file mode 100644
index 000000000..b7408feb9
--- /dev/null
+++ b/mistral/dsl_parser.py
@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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 yaml
+from yaml import error
+from mistral.workbook import workbook
+
+
+def parse(workbook_definition):
+    """Loads a workbook definition in YAML format as dictionary object."""
+    try:
+        return yaml.safe_load(workbook_definition)
+    except error.YAMLError as exc:
+        raise RuntimeError("Definition could not be parsed: %s\n" % exc)
+
+
+def get_workbook(workbook_definition):
+    return workbook.WorkbookSpec(parse(workbook_definition))
diff --git a/mistral/engine/abstract_engine.py b/mistral/engine/abstract_engine.py
index 3746b9101..9e4c48078 100644
--- a/mistral/engine/abstract_engine.py
+++ b/mistral/engine/abstract_engine.py
@@ -18,7 +18,7 @@ import abc
 
 from mistral.openstack.common import log as logging
 from mistral.db import api as db_api
-from mistral import dsl
+from mistral import dsl_parser as parser
 from mistral import exceptions as exc
 from mistral.engine import states
 from mistral.engine import workflow
@@ -38,19 +38,17 @@ class AbstractEngine(object):
     def start_workflow_execution(cls, workbook_name, task_name, context):
         db_api.start_tx()
 
+        workbook = cls._get_workbook(workbook_name)
         # Persist execution and tasks in DB.
         try:
-            wb_dsl = cls._get_wb_dsl(workbook_name)
-
             execution = cls._create_execution(workbook_name,
                                               task_name,
                                               context)
 
             tasks = cls._create_tasks(
-                workflow.find_workflow_tasks(wb_dsl, task_name),
-                wb_dsl,
-                workbook_name,
-                execution['id']
+                workflow.find_workflow_tasks(workbook, task_name),
+                workbook,
+                workbook_name, execution['id']
             )
 
             tasks_to_start = workflow.find_resolved_tasks(tasks)
@@ -73,10 +71,9 @@ class AbstractEngine(object):
                            task_id, state, result):
         db_api.start_tx()
 
+        workbook = cls._get_workbook(workbook_name)
         try:
-            wb_dsl = cls._get_wb_dsl(workbook_name)
             #TODO(rakhmerov): validate state transition
-
             task = db_api.task_get(workbook_name, execution_id, task_id)
 
             task_output = data_flow.get_task_output(task, result)
@@ -90,7 +87,7 @@ class AbstractEngine(object):
             # Calculate task outbound context.
             outbound_context = data_flow.get_outbound_context(task)
 
-            cls._create_next_tasks(task, wb_dsl)
+            cls._create_next_tasks(task, workbook)
 
             # Determine what tasks need to be started.
             tasks = db_api.tasks_get(workbook_name, execution_id)
@@ -159,38 +156,37 @@ class AbstractEngine(object):
         })
 
     @classmethod
-    def _create_next_tasks(cls, task, wb_dsl):
-        dsl_tasks = workflow.find_tasks_after_completion(task, wb_dsl)
+    def _create_next_tasks(cls, task, workbook):
+        tasks = workflow.find_tasks_after_completion(task, workbook)
 
-        tasks = cls._create_tasks(dsl_tasks, wb_dsl, task['workbook_name'],
-                                  task['execution_id'])
+        db_tasks = cls._create_tasks(tasks, workbook, task['workbook_name'],
+                                     task['execution_id'])
 
-        return workflow.find_resolved_tasks(tasks)
+        return workflow.find_resolved_tasks(db_tasks)
 
     @classmethod
-    def _create_tasks(cls, dsl_tasks, wb_dsl, workbook_name, execution_id):
+    def _create_tasks(cls, task_list, workbook, workbook_name, execution_id):
         tasks = []
 
-        for dsl_task in dsl_tasks:
-            task = db_api.task_create(workbook_name, execution_id, {
-                "name": dsl_task["name"],
-                "requires": dsl_task.get("requires", {}),
-                "task_dsl": dsl_task,
-                "service_dsl": wb_dsl.get_service(dsl_task["service_name"]),
+        for task in task_list:
+            db_task = db_api.task_create(workbook_name, execution_id, {
+                "name": task.name,
+                "requires": task.requires,
+                "task_spec": task.to_dict(),
+                "service_spec": workbook.services.get(
+                    task.get_action_service()).to_dict(),
                 "state": states.IDLE,
-                "tags": dsl_task.get("tags", None)
+                "tags": task.get_property("tags", None)
             })
 
-            tasks.append(task)
+            tasks.append(db_task)
 
         return tasks
 
     @classmethod
-    def _get_wb_dsl(cls, workbook_name):
+    def _get_workbook(cls, workbook_name):
         wb = db_api.workbook_get(workbook_name)
-        wb_dsl = dsl.Parser(wb["definition"])
-
-        return wb_dsl
+        return parser.get_workbook(wb["definition"])
 
     @classmethod
     def _determine_execution_state(cls, execution, tasks):
diff --git a/mistral/engine/actions/action_factory.py b/mistral/engine/actions/action_factory.py
index 7ae038167..1435a4145 100644
--- a/mistral/engine/actions/action_factory.py
+++ b/mistral/engine/actions/action_factory.py
@@ -18,17 +18,21 @@ from mistral.engine.actions import actions
 from mistral.engine.actions import action_types
 from mistral.engine.actions import action_helper as a_h
 import mistral.exceptions as exc
+from mistral.workbook import services
+from mistral.workbook import tasks
 
 
-def create_action(task):
-    action_type = a_h.get_action_type(task)
+def create_action(db_task):
+    action_type = a_h.get_action_type(db_task)
+    task = tasks.TaskSpec(db_task['task_spec'])
+    service = services.ServiceSpec(db_task['service_spec'])
 
     if not action_types.is_valid(action_type):
         raise exc.InvalidActionException("Action type is not supported: %s" %
                                          action_type)
 
-    action = _get_mapping()[action_type](task)
-    action.result_helper = _find_action_result_helper(task, action)
+    action = _get_mapping()[action_type](db_task, task, service)
+    action.result_helper = _find_action_result_helper(db_task, action)
     return action
 
 
@@ -44,33 +48,33 @@ def _get_mapping():
 
 def _find_action_result_helper(task, action):
     try:
-        return task['service_dsl']['actions'][action.name].get('output', {})
+        return task['service_spec']['actions'][action.name].get('output', {})
     except (KeyError, AttributeError):
         return {}
 
 
-def get_echo_action(task):
-    action_type = a_h.get_action_type(task)
-    action_name = task['task_dsl']['action'].split(':')[1]
+def get_echo_action(db_task, task, service):
+    action_type = service.type
+    action_name = task.get_action_name()
 
-    output = task['service_dsl']['actions'][action_name].get('output', {})
+    output = service.actions.get(action_name).output
 
     return actions.EchoAction(action_type, action_name, output=output)
 
 
-def get_rest_action(task):
-    action_type = a_h.get_action_type(task)
-    action_name = task['task_dsl']['action'].split(':')[1]
-    action_dsl = task['service_dsl']['actions'][action_name]
-    task_params = task['task_dsl'].get('parameters', {})
-    url = task['service_dsl']['parameters']['baseUrl'] +\
-        action_dsl['parameters']['url']
+def get_rest_action(db_task, task, service):
+    action_type = service.type
+    action_name = task.get_action_name()
+    action = service.actions.get(action_name)
+    task_params = task.parameters
+    url = service.parameters['baseUrl'] +\
+        action.parameters['url']
 
     headers = {}
-    headers.update(task['task_dsl'].get('headers', {}))
-    headers.update(action_dsl.get('headers', {}))
+    headers.update(task.parameters.get('headers', {}))
+    headers.update(action.parameters.get('headers', {}))
 
-    method = action_dsl['parameters'].get('method', "GET")
+    method = action.parameters.get('method', "GET")
 
     # input_yaql = task.get('input')
     # TODO(nmakhotkin) extract input from context with the YAQL expression
@@ -87,25 +91,26 @@ def get_rest_action(task):
                               headers=headers, data=task_data)
 
 
-def get_mistral_rest_action(task):
+def get_mistral_rest_action(db_task, task, service):
     mistral_headers = {
-        'Mistral-Workbook-Name': task['workbook_name'],
-        'Mistral-Execution-Id': task['execution_id'],
-        'Mistral-Task-Id': task['id'],
+        'Mistral-Workbook-Name': db_task['workbook_name'],
+        'Mistral-Execution-Id': db_task['execution_id'],
+        'Mistral-Task-Id': db_task['id'],
     }
 
-    action = get_rest_action(task)
+    action = get_rest_action(db_task, task, service)
     action.headers.update(mistral_headers)
 
     return action
 
 
-def get_amqp_action(task):
-    action_type = a_h.get_action_type(task)
-    action_name = task['task_dsl']['action'].split(':')[1]
-    action_params = task['service_dsl']['actions'][action_name]['parameters']
-    task_params = task['task_dsl'].get('parameters', {})
-    service_parameters = task['service_dsl'].get('parameters', {})
+def get_amqp_action(db_task, task, service):
+    action_type = service.type
+    action_name = task.get_action_name()
+    action = service.actions.get(action_name)
+    action_params = action.parameters
+    task_params = task.parameters
+    service_parameters = service.parameters
 
     host = service_parameters['host']
     port = service_parameters.get('port')
@@ -117,18 +122,18 @@ def get_amqp_action(task):
     exchange = action_params.get('exchange')
     queue_name = action_params['queue_name']
 
-    return actions.OsloRPCAction(action_type, host, userid, password,
-                                 virtual_host, message, routing_key, port,
-                                 exchange, queue_name)
+    return actions.OsloRPCAction(action_type, action_name, host, userid,
+                                 password, virtual_host, message, routing_key,
+                                 port, exchange, queue_name)
 
 
-def get_send_email_action(task):
+def get_send_email_action(db_task, task, service):
     #TODO(dzimine): Refactor action_type and action_name settings
     #               for all actions
-    action_type = a_h.get_action_type(task)
-    action_name = task['task_dsl']['action'].split(':')[1]
-    task_params = task['task_dsl'].get('parameters', {})
-    service_params = task['service_dsl'].get('parameters', {})
+    action_type = service.type
+    action_name = task.get_action_name()
+    task_params = task.parameters
+    service_params = service.parameters
 
     return actions.SendEmailAction(action_type, action_name,
                                    task_params, service_params)
diff --git a/mistral/engine/actions/action_helper.py b/mistral/engine/actions/action_helper.py
index 620f5f4b0..66a23de11 100644
--- a/mistral/engine/actions/action_helper.py
+++ b/mistral/engine/actions/action_helper.py
@@ -18,7 +18,7 @@ from mistral.engine.actions import action_types as a_t
 
 
 def get_action_type(task):
-    return task['service_dsl']['type']
+    return task['service_spec']['type']
 
 
 def is_task_synchronous(task):
diff --git a/mistral/engine/data_flow.py b/mistral/engine/data_flow.py
index 5bd1d66a9..4ebda5299 100644
--- a/mistral/engine/data_flow.py
+++ b/mistral/engine/data_flow.py
@@ -25,7 +25,7 @@ LOG = logging.getLogger(__name__)
 def evaluate_task_input(task, context):
     res = {}
 
-    params = task['task_dsl'].get('input', {})
+    params = task['task_spec'].get('input', {})
 
     if not params:
         return res
@@ -54,7 +54,7 @@ def prepare_tasks(tasks, context):
 
 
 def get_task_output(task, result):
-    vars_to_publish = task['task_dsl'].get('publish')
+    vars_to_publish = task['task_spec'].get('publish')
 
     output = {}
 
diff --git a/mistral/engine/scalable/executor/server.py b/mistral/engine/scalable/executor/server.py
index 2d3af13da..47e687fcb 100644
--- a/mistral/engine/scalable/executor/server.py
+++ b/mistral/engine/scalable/executor/server.py
@@ -36,8 +36,8 @@ class Executor(object):
         """
         LOG.info("Starting task action [task_id=%s, "
                  "action='%s', service='%s'" %
-                 (task['id'], task['task_dsl']['action'],
-                  task['service_dsl']))
+                 (task['id'], task['task_spec']['action'],
+                  task['service_spec']))
 
         action = a_f.create_action(task)
 
diff --git a/mistral/engine/workflow.py b/mistral/engine/workflow.py
index 02c89471c..406800c1e 100644
--- a/mistral/engine/workflow.py
+++ b/mistral/engine/workflow.py
@@ -24,20 +24,18 @@ from mistral.openstack.common import log as logging
 LOG = logging.getLogger(__name__)
 
 
-def find_workflow_tasks(wb_dsl, task_name):
-    dsl_tasks = wb_dsl.get_tasks()
+def find_workflow_tasks(workbook, task_name):
+    wb_tasks = workbook.tasks
     full_graph = nx.DiGraph()
-    for t in dsl_tasks:
+    for t in wb_tasks:
         full_graph.add_node(t)
 
-    _update_dependencies(dsl_tasks, full_graph)
+    _update_dependencies(wb_tasks, full_graph)
 
     graph = _get_subgraph(full_graph, task_name)
     tasks = []
     for node in graph:
-        task = {'name': node}
-        task.update(dsl_tasks[node])
-        tasks.append(task)
+        tasks.append(wb_tasks[node])
 
     return tasks
 
@@ -55,45 +53,44 @@ def _get_checked_tasks(target_tasks):
     return checked_tasks
 
 
-def _get_tasks_to_schedule(target_tasks, wb_dsl):
+def _get_tasks_to_schedule(target_tasks, workbook):
     tasks_to_schedule = _get_checked_tasks(target_tasks)
-    return [wb_dsl.get_task(t_name) for t_name in tasks_to_schedule]
+    return [workbook.tasks.get(t_name) for t_name in tasks_to_schedule]
 
 
-def find_tasks_after_completion(task, wb_dsl):
+def find_tasks_after_completion(task, workbook):
     """Determine tasks which should be scheduled after completing
     given task. Expression 'on_finish' is not mutually exclusive to
     'on_success' and 'on_error'.
 
     :param task: Task object
-    :param wb_dsl: DSL Parser
-    :return: list of DSL tasks.
+    :param workbook: Workbook Entity
+    :return: list of task dictionaries.
     """
     state = task['state']
     found_tasks = []
     LOG.debug("Recieved task %s: %s" % (task['name'], state))
 
     if state == states.ERROR:
-        tasks_on_error = wb_dsl.get_task_on_error(task['name'])
+        tasks_on_error = workbook.tasks.get(task['name']).get_on_error()
         if tasks_on_error:
-            found_tasks = _get_tasks_to_schedule(tasks_on_error, wb_dsl)
+            found_tasks = _get_tasks_to_schedule(tasks_on_error, workbook)
 
     elif state == states.SUCCESS:
-        tasks_on_success = wb_dsl.get_task_on_success(task['name'])
+        tasks_on_success = workbook.tasks.get(task['name']).get_on_success()
         if tasks_on_success:
-            found_tasks = _get_tasks_to_schedule(tasks_on_success, wb_dsl)
+            found_tasks = _get_tasks_to_schedule(tasks_on_success, workbook)
 
     if states.is_finished(state):
-        tasks_on_finish = wb_dsl.get_task_on_finish(task['name'])
+        tasks_on_finish = workbook.tasks.get(task['name']).get_on_finish()
         if tasks_on_finish:
-            found_tasks += _get_tasks_to_schedule(tasks_on_finish, wb_dsl)
+            found_tasks += _get_tasks_to_schedule(tasks_on_finish, workbook)
 
     LOG.debug("Found tasks: %s" % found_tasks)
 
     workflow_tasks = []
     for t in found_tasks:
-        workflow_tasks += find_workflow_tasks(wb_dsl, t['name'])
-
+        workflow_tasks += find_workflow_tasks(workbook, t.name)
     LOG.debug("Workflow tasks to schedule: %s" % workflow_tasks)
 
     return workflow_tasks
@@ -120,12 +117,12 @@ def _get_subgraph(full_graph, task_name):
 
 
 def _get_dependency_tasks(tasks, task):
-    if 'requires' not in tasks[task]:
+    if len(tasks[task].requires) < 1:
         return []
 
     deps = set()
     for t in tasks:
-        for dep in tasks[task]['requires']:
+        for dep in tasks[task].requires:
             if dep == t:
                 deps.add(t)
 
diff --git a/mistral/exceptions.py b/mistral/exceptions.py
index 0bc40b010..7461931b0 100644
--- a/mistral/exceptions.py
+++ b/mistral/exceptions.py
@@ -85,3 +85,13 @@ class ApplicationContextNotFoundException(MistralException):
         super(ApplicationContextNotFoundException, self).__init__(message)
         if message:
             self.message = message
+
+
+class InvalidModelException(MistralException):
+    message = "Wrong entity definition"
+    code = "INVALID_MODEL_EXCEPTION"
+
+    def __init__(self, message=None):
+        super(InvalidModelException, self).__init__(message)
+        if message:
+            self.message = message
diff --git a/mistral/services/periodic.py b/mistral/services/periodic.py
index 7d773b2f9..b45331174 100644
--- a/mistral/services/periodic.py
+++ b/mistral/services/periodic.py
@@ -21,7 +21,7 @@ from mistral.openstack.common import log
 from mistral.openstack.common import periodic_task
 from mistral.openstack.common import threadgroup
 from mistral import context
-from mistral import dsl
+from mistral import dsl_parser as parser
 from mistral.services import scheduler as sched
 from mistral.services import trusts
 
@@ -38,7 +38,7 @@ class MistralPeriodicTasks(periodic_task.PeriodicTasks):
             context.set_ctx(trusts.create_context(wb))
 
             try:
-                task = dsl.Parser(
+                task = parser.get_workbook(
                     wb['definition']).get_event_task_name(event['name'])
                 engine.start_workflow_execution(wb['name'], task)
             finally:
diff --git a/mistral/services/scheduler.py b/mistral/services/scheduler.py
index 9628ecf6f..470e4ccb0 100644
--- a/mistral/services/scheduler.py
+++ b/mistral/services/scheduler.py
@@ -18,7 +18,7 @@ from croniter import croniter
 from datetime import datetime
 from datetime import timedelta
 from mistral.db import api as db_api
-from mistral import dsl
+from mistral import dsl_parser as parser
 
 
 def get_next_events():
@@ -50,30 +50,30 @@ def create_event(name, pattern, workbook_name, start_time=None):
     })
 
 
-def create_associated_events(workbook):
-    if not workbook['definition']:
+def create_associated_events(db_workbook):
+    if not db_workbook['definition']:
         return
 
-    parser = dsl.Parser(workbook['definition'])
-    dsl_events = parser.get_events()
+    workbook = parser.get_workbook(db_workbook['definition'])
+    triggers = workbook.get_triggers()
 
     # Prepare all events data in advance to make db transaction shorter.
-    events = []
+    db_triggers = []
 
-    for e in dsl_events:
+    for e in triggers:
         pattern = e['parameters']['cron-pattern']
         next_time = _get_next_execution_time(pattern, datetime.now())
-        events.append({
+        db_triggers.append({
             "name": e['name'],
             "pattern": pattern,
             "next_execution_time": next_time,
-            "workbook_name": workbook['name']
+            "workbook_name": db_workbook['name']
         })
 
     db_api.start_tx()
 
     try:
-        for e in events:
+        for e in db_triggers:
             db_api.event_create(e)
 
         db_api.commit_tx()
diff --git a/mistral/tests/api/v1/controllers/test_workbook_definition.py b/mistral/tests/api/v1/controllers/test_workbook_definition.py
index 850cd390e..6eea7b1e6 100644
--- a/mistral/tests/api/v1/controllers/test_workbook_definition.py
+++ b/mistral/tests/api/v1/controllers/test_workbook_definition.py
@@ -24,13 +24,23 @@ from mistral.db import api as db_api
 DEFINITION = "my definition"
 
 NEW_DEFINITION = """
+Services:
+  Service:
+    type:
+    actions:
+      action:
+        parameters:
 Workflow:
-    events:
-        create-vms:
-            type: periodic
-            tasks: create-vms
-            parameters:
-                cron-pattern: "* * * * *"
+  tasks:
+    task1:
+      parameters:
+      action: Service:action
+triggers:
+  create-vms:
+    type: periodic
+    tasks: create-vms
+    parameters:
+      cron-pattern: "* * * * *"
 """
 
 
diff --git a/mistral/tests/resources/test_amqp.yaml b/mistral/tests/resources/test_amqp.yaml
index 7c6d3f5de..583687fae 100644
--- a/mistral/tests/resources/test_amqp.yaml
+++ b/mistral/tests/resources/test_amqp.yaml
@@ -29,9 +29,9 @@ Workflow:
            routing_key: my_key
            message: MyMessage
 
-   events:
-     backup-vm:
-        type: periodic
-        tasks: send-messages
-        parameters:
-            cron-pattern: 1 0 * * *
\ No newline at end of file
+triggers:
+  backup-vm:
+    type: periodic
+    tasks: send-messages
+    parameters:
+      cron-pattern: 1 0 * * *
\ No newline at end of file
diff --git a/mistral/tests/resources/test_rest.yaml b/mistral/tests/resources/test_rest.yaml
index b485179c7..c8b093242 100644
--- a/mistral/tests/resources/test_rest.yaml
+++ b/mistral/tests/resources/test_rest.yaml
@@ -93,9 +93,9 @@ Workflow:
         on-finish:
           create-vms
 
-   events:
-     create-vms:
-        type: periodic
-        tasks: create-vms
-        parameters:
-            cron-pattern: "* * * * *"
+triggers:
+  create-vms:
+    type: periodic
+    tasks: create-vms
+    parameters:
+      cron-pattern: "* * * * *"
diff --git a/mistral/tests/unit/db/test_sqlalchemy_db_api.py b/mistral/tests/unit/db/test_sqlalchemy_db_api.py
index 2a9b609a5..760965ce1 100644
--- a/mistral/tests/unit/db/test_sqlalchemy_db_api.py
+++ b/mistral/tests/unit/db/test_sqlalchemy_db_api.py
@@ -223,8 +223,8 @@ TASKS = [
         'name': 'my_task1',
         'description': 'my description',
         'requires': {'my_task2': '', 'my_task3': ''},
-        'task_dsl': None,
-        'service_dsl': None,
+        'task_spec': None,
+        'service_spec': None,
         'action': {'name': 'Nova:create-vm'},
         'state': 'IDLE',
         'tags': ['deployment'],
@@ -240,8 +240,8 @@ TASKS = [
         'name': 'my_task2',
         'description': 'my description',
         'requires': {'my_task4': '', 'my_task5': ''},
-        'task_dsl': None,
-        'service_dsl': None,
+        'task_spec': None,
+        'service_spec': None,
         'action': {'name': 'Cinder:create-volume'},
         'state': 'IDLE',
         'tags': ['deployment'],
diff --git a/mistral/tests/unit/engine/actions/test_action_factory.py b/mistral/tests/unit/engine/actions/test_action_factory.py
index 3c0adabcc..3674f3baf 100644
--- a/mistral/tests/unit/engine/actions/test_action_factory.py
+++ b/mistral/tests/unit/engine/actions/test_action_factory.py
@@ -21,16 +21,17 @@ from mistral.engine.actions import action_types
 
 
 SAMPLE_TASK = {
-    'task_dsl': {
+    'task_spec': {
         'action': 'MyRest:create-vm',
         'parameters': {
             'a': 'b'
         },
         'headers': {
             'Cookie': 'abc'
-        }
+        },
+        'name': 'create-vms'
     },
-    'service_dsl': {
+    'service_spec': {
         'parameters': {
             'baseUrl': 'http://some_host'
         },
@@ -40,11 +41,14 @@ SAMPLE_TASK = {
                     'url': '/task1'
                 }
             }
-        }
+        },
+        'type': 'REST_API',
+        'name': 'MyRest'
     },
     'workbook_name': 'wb',
     'execution_id': '1234',
-    'id': '123'
+    'id': '123',
+    'name': 'create-vms'
 }
 
 SAMPLE_SEND_EMAIL_TASK = {
@@ -55,7 +59,7 @@ SAMPLE_SEND_EMAIL_TASK = {
     'id': '800f52c4-1ba9-45ac-ba81-c4d2a7863738',
     'execution_id': '645f042f-09cb-43ca-bee7-94f592409a7d',
     'state': 'IDLE',
-    'service_dsl': {
+    'service_spec': {
         'type': "SEND_EMAIL",
         'parameters': {
             'smtp_server': "localhost:25",
@@ -64,10 +68,11 @@ SAMPLE_SEND_EMAIL_TASK = {
             # password: None
         },
         'actions': {
-            'send_email': ''
-        }
+            'send_email': {}
+        },
+        'name': 'send_email'
     },
-    'task_dsl': {
+    'task_spec': {
         'name': 'backup_user_data',
         'parameters': {
             'to': ["dz@example.com, deg@example.com", "xyz@example.com"],
@@ -96,7 +101,7 @@ SAMPLE_RESULT = {
 class ActionFactoryTest(unittest2.TestCase):
     def test_get_mistral_rest(self):
         task = dict(SAMPLE_TASK)
-        task['service_dsl'].update({'type': action_types.MISTRAL_REST_API})
+        task['service_spec'].update({'type': action_types.MISTRAL_REST_API})
         action = action_factory.create_action(task)
 
         self.assertIn("Mistral-Workbook-Name", action.headers)
@@ -104,7 +109,7 @@ class ActionFactoryTest(unittest2.TestCase):
 
     def test_get_rest(self):
         task = dict(SAMPLE_TASK)
-        task['service_dsl'].update({'type': action_types.REST_API})
+        task['service_spec'].update({'type': action_types.REST_API})
         action = action_factory.create_action(task)
 
         self.assertNotIn("Mistral-Workbook-Name", action.headers)
@@ -117,7 +122,7 @@ class ActionFactoryTest(unittest2.TestCase):
         #NOTE(dzimine): Implement parameter validation in action,
         # and this will be the only validation we need.
         # Smoke-test one from task and one from service
-        for email in task['task_dsl']['parameters']['to']:
+        for email in task['task_spec']['parameters']['to']:
             self.assertIn(email, action.to)
-        self.assertEqual(task['service_dsl']['parameters']['smtp_server'],
+        self.assertEqual(task['service_spec']['parameters']['smtp_server'],
                          action.smtp_server)
diff --git a/mistral/tests/unit/engine/scalable/test_executor.py b/mistral/tests/unit/engine/scalable/test_executor.py
index ef5456170..eb625c67e 100644
--- a/mistral/tests/unit/engine/scalable/test_executor.py
+++ b/mistral/tests/unit/engine/scalable/test_executor.py
@@ -39,7 +39,7 @@ SAMPLE_WORKBOOK = {
     'id': str(uuid.uuid4()),
     'name': WORKBOOK_NAME,
     'description': 'my description',
-    'definition': '{}',
+    'definition': base.get_resource("test_rest.yaml"),
     'tags': [],
     'scope': 'public',
     'updated_at': None,
@@ -59,7 +59,7 @@ SAMPLE_EXECUTION = {
 SAMPLE_TASK = {
     'name': TASK_NAME,
     'workbook_name': WORKBOOK_NAME,
-    'service_dsl': {
+    'service_spec': {
         'type': action_types.REST_API,
         'parameters': {
             'baseUrl': 'http://localhost:8989/v1/'},
@@ -67,8 +67,10 @@ SAMPLE_TASK = {
             'my-action': {
                 'parameters': {
                     'url': 'workbooks',
-                    'method': 'GET'}}}},
-    'task_dsl': {
+                    'method': 'GET'}}},
+        'name': 'MyService'
+    },
+    'task_spec': {
         'action': 'MyRest:my-action',
         'service_name': 'MyRest',
         'name': TASK_NAME},
@@ -109,6 +111,7 @@ class TestExecutor(base.DbTestCase):
 
     def setUp(self):
         # Initialize configuration for the ExecutorClient.
+        super(TestExecutor, self).setUp()
         if not 'executor' in cfg.CONF:
             cfg_grp = cfg.OptGroup(name='executor', title='Executor options')
             opts = [cfg.StrOpt('host', default='0.0.0.0'),
@@ -124,8 +127,6 @@ class TestExecutor(base.DbTestCase):
                                                endpoints, executor='eventlet')
         self.server.start()
 
-        super(TestExecutor, self).setUp()
-
     def tearDown(self):
         # Stop the Executor.
         if self.server:
diff --git a/mistral/tests/unit/engine/test_data_flow_module.py b/mistral/tests/unit/engine/test_data_flow_module.py
index ca8ef1134..8e4e3880e 100644
--- a/mistral/tests/unit/engine/test_data_flow_module.py
+++ b/mistral/tests/unit/engine/test_data_flow_module.py
@@ -38,7 +38,7 @@ TASK = {
     'workbook_name': WB_NAME,
     'execution_id': EXEC_ID,
     'name': 'my_task',
-    'task_dsl': {
+    'task_spec': {
         'input': {
             'p1': 'My string',
             'p2': '$.param3.param32'
diff --git a/mistral/tests/unit/engine/test_workflow.py b/mistral/tests/unit/engine/test_workflow.py
index 4fb97d4ef..efe60e1f8 100644
--- a/mistral/tests/unit/engine/test_workflow.py
+++ b/mistral/tests/unit/engine/test_workflow.py
@@ -16,9 +16,9 @@
 
 import pkg_resources as pkg
 
-from mistral import dsl
 from mistral import version
 from mistral.tests import base
+from mistral import dsl_parser as parser
 from mistral.engine import states
 from mistral.engine import workflow
 
@@ -47,11 +47,11 @@ class WorkflowTest(base.DbTestCase):
         self.doc = open(pkg.resource_filename(
             version.version_info.package,
             "tests/resources/test_rest.yaml")).read()
-        self.parser = dsl.Parser(self.doc)
+        self.parser = parser.get_workbook(self.doc)
 
     def test_find_workflow_tasks(self):
         tasks = workflow.find_workflow_tasks(self.parser, "attach-volumes")
-        self.assertEqual(tasks[1]['name'], 'create-vms')
+        self.assertEqual(tasks[1].name, 'create-vms')
 
     def test_tasks_to_start(self):
         tasks_to_start = workflow.find_resolved_tasks(TASKS)
diff --git a/mistral/tests/unit/events/test_events.py b/mistral/tests/unit/events/test_events.py
index 20e5d52e1..19ccb6663 100644
--- a/mistral/tests/unit/events/test_events.py
+++ b/mistral/tests/unit/events/test_events.py
@@ -17,7 +17,6 @@
 import pkg_resources as pkg
 
 from mistral.db import api as db_api
-from mistral import dsl
 from mistral.tests import base
 from mistral import version
 from mistral.services import scheduler
@@ -29,7 +28,6 @@ class EventsTest(base.DbTestCase):
         self.doc = open(pkg.resource_filename(
             version.version_info.package,
             "tests/resources/test_rest.yaml")).read()
-        self.dsl = dsl.Parser(self.doc)
 
     def test_create_associated_events(self):
         workbook = {
diff --git a/mistral/tests/unit/test_parser.py b/mistral/tests/unit/test_parser.py
deleted file mode 100644
index 85a324851..000000000
--- a/mistral/tests/unit/test_parser.py
+++ /dev/null
@@ -1,81 +0,0 @@
-# -*- coding: utf-8 -*-
-#
-# Copyright 2013 - Mirantis, Inc.
-#
-#    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 pkg_resources as pkg
-import unittest2
-
-from mistral import dsl
-from mistral import version
-
-
-class DSLParserTest(unittest2.TestCase):
-    def setUp(self):
-        doc = open(pkg.resource_filename(
-            version.version_info.package,
-            "tests/resources/test_rest.yaml")).read()
-        self.dsl = dsl.Parser(doc)
-
-    def test_services(self):
-        service = self.dsl.get_service("MyRest")
-        self.assertEqual(service["type"], "MISTRAL_REST_API")
-        self.assertIn("baseUrl", service["parameters"])
-        services = self.dsl.get_services()
-        self.assertEqual(len(services), 2)
-        service_names = self.dsl.get_service_names()
-        self.assertEqual(service_names[0], "MyRest")
-
-    def test_events(self):
-        events = self.dsl.get_events()
-        self.assertIn("create-vms", events[0]['name'])
-
-        event_task_name = self.dsl.get_event_task_name("create-vms")
-        self.assertEqual(event_task_name, "create-vms")
-        event_task_name = self.dsl.get_event_task_name("not-valid")
-        self.assertEqual(event_task_name, "")
-
-    def test_tasks(self):
-        tasks = self.dsl.get_tasks()
-        self.assertIn("create-vms", tasks)
-        self.assertIn("parameters", tasks["create-vms"])
-        self.assertEqual(tasks["backup-vms"]["action"],
-                         "MyRest:backup-vm")
-        attach_parameters = self.dsl.get_task_dsl_property("attach-volumes",
-                                                           "parameters")
-        self.assertIn("size", attach_parameters)
-        self.assertIn("mnt_path", attach_parameters)
-        task = self.dsl.get_task("not-valid-name")
-        self.assertEqual(task, {})
-
-    def test_task_property(self):
-        on_success = self.dsl.get_task_on_success("test_subsequent")
-        self.assertEqual(on_success, {"attach-volumes": ''})
-        on_error = self.dsl.get_task_on_error("test_subsequent")
-        self.assertEqual(on_error, {"backup-vms": "$.status != 'OK'"})
-
-    def test_actions(self):
-        action = self.dsl.get_action("MyRest:attach-volume")
-        self.assertIn("method", action["parameters"])
-        actions = self.dsl.get_actions("MyRest")
-        self.assertIn("task-parameters", actions["attach-volume"])
-
-    def test_broken_definition(self):
-        broken_yaml = """
-        Workflow:
-          [tasks:
-            create-vms/:
-
-        """
-        self.assertRaises(RuntimeError, dsl.Parser, broken_yaml)
diff --git a/mistral/tests/unit/workbook/__init__.py b/mistral/tests/unit/workbook/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/mistral/tests/unit/workbook/test_workbook.py b/mistral/tests/unit/workbook/test_workbook.py
new file mode 100644
index 000000000..e2ffb9234
--- /dev/null
+++ b/mistral/tests/unit/workbook/test_workbook.py
@@ -0,0 +1,76 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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 pkg_resources as pkg
+import unittest2
+
+from mistral.engine.actions import action_types as a_t
+from mistral import dsl_parser as parser
+from mistral import version
+
+
+class DSLModelTest(unittest2.TestCase):
+    def setUp(self):
+        self.doc = open(pkg.resource_filename(
+            version.version_info.package,
+            "tests/resources/test_rest.yaml")).read()
+
+    def test_load_dsl(self):
+        self.workbook = parser.get_workbook(self.doc)
+        self.assertEqual(self.workbook.workflow.tasks.items,
+                         self.workbook.tasks.items)
+        self.assertEqual(self.workbook.tasks.get("create-vms").name,
+                         "create-vms")
+        self.assertEqual(self.workbook.services.get("MyRest").type,
+                         "MISTRAL_REST_API")
+
+    def test_tasks(self):
+        self.workbook = parser.get_workbook(self.doc)
+        self.assertEqual(len(self.workbook.tasks), 6)
+        attach_volumes = self.workbook.tasks.get("attach-volumes")
+        self.assertEqual(attach_volumes.get_action_service(), "MyRest")
+        t_parameters = {"image_id": 1234, "flavor_id": 2}
+        create_vm_nova = self.workbook.tasks.get("create-vm-nova")
+        self.assertEqual(create_vm_nova.parameters, t_parameters)
+        attach_requires = {"create-vms": ''}
+        self.assertEqual(attach_volumes.requires, attach_requires)
+        subsequent = self.workbook.tasks.get("test_subsequent")
+        subseq_success = subsequent.get_on_success()
+        subseq_error = subsequent.get_on_error()
+        subseq_finish = subsequent.get_on_finish()
+        self.assertEqual(subseq_success, {"attach-volumes": ''})
+        self.assertEqual(subseq_error, {"backup-vms": "$.status != 'OK'"})
+        self.assertEqual(subseq_finish, {"create-vms": ''})
+
+    def test_actions(self):
+        self.workbook = parser.get_workbook(self.doc)
+        actions = self.workbook.services.get("MyRest").actions
+        self.assertEqual(len(actions), 4)
+        create_vm = actions.get("create-vm")
+        self.assertIn('method', create_vm.parameters)
+
+    def test_services(self):
+        self.workbook = parser.get_workbook(self.doc)
+        services = self.workbook.services
+        self.assertEqual(len(services), 2)
+        nova_service = services.get("Nova")
+        self.assertEqual(nova_service.type, a_t.REST_API)
+        self.assertIn("baseUrl", nova_service.parameters)
+
+    def test_triggers(self):
+        self.workbook = parser.get_workbook(self.doc)
+        triggers = self.workbook.get_triggers()
+        self.assertEqual(len(triggers), 1)
diff --git a/mistral/workbook/__init__.py b/mistral/workbook/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/mistral/workbook/actions.py b/mistral/workbook/actions.py
new file mode 100644
index 000000000..c26bd92fc
--- /dev/null
+++ b/mistral/workbook/actions.py
@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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.
+
+from mistral.workbook import base
+
+
+class ActionSpec(base.BaseSpec):
+    _required_keys = ['name']
+
+    def __init__(self, action):
+        super(ActionSpec, self).__init__(action)
+        if self.validate():
+            self.name = action['name']
+            self.parameters = action.get('parameters', {})
+            self.input = action.get('input', {})
+            self.output = action.get('output', {})
+            self.task_parameters = action.get('task-parameters', {})
+
+
+class ActionSpecList(base.BaseSpecList):
+    item_class = ActionSpec
diff --git a/mistral/workbook/base.py b/mistral/workbook/base.py
new file mode 100644
index 000000000..ac8f5ae9d
--- /dev/null
+++ b/mistral/workbook/base.py
@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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 collections
+
+from mistral import exceptions
+
+
+class BaseSpec(object):
+    _required_keys = []
+
+    def __init__(self, data):
+        self._data = data
+
+    def validate(self):
+        if not all(k in self._data for k in self._required_keys):
+            message = ("Wrong model definition for: %s. It should contain"
+                       " required keys: %s" % (self.__class__.__name__,
+                                               self._required_keys))
+            raise exceptions.InvalidModelException(message)
+        return True
+
+    def to_dict(self):
+        return self._data
+
+
+class BaseSpecList(object):
+    item_class = None
+
+    def __init__(self, data):
+        self.items = collections.OrderedDict()
+        for k, v in data.items():
+            item = data[k]
+            item.update({'name': k})
+            self.items.update({k: self.item_class(item)})
+        for name in self:
+            self.get(name).validate()
+
+    def __iter__(self):
+        return iter(self.items)
+
+    def __getitem__(self, name):
+        return self.items.get(name)
+
+    def __len__(self):
+        return len(self.items)
+
+    def get(self, name):
+        return self.__getitem__(name)
diff --git a/mistral/workbook/services.py b/mistral/workbook/services.py
new file mode 100644
index 000000000..f2125860f
--- /dev/null
+++ b/mistral/workbook/services.py
@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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.
+
+from mistral.workbook import actions
+from mistral.workbook import base
+
+
+class ServiceSpec(base.BaseSpec):
+    _required_keys = ['name', 'type', 'actions']
+
+    def __init__(self, service):
+        super(ServiceSpec, self).__init__(service)
+        if self.validate():
+            self.type = service['type']
+            self.name = service['name']
+            self.parameters = service.get('parameters', {})
+            self.actions = actions.ActionSpecList(service['actions'])
+
+
+class ServiceSpecList(base.BaseSpecList):
+    item_class = ServiceSpec
diff --git a/mistral/workbook/tasks.py b/mistral/workbook/tasks.py
new file mode 100644
index 000000000..e471a954a
--- /dev/null
+++ b/mistral/workbook/tasks.py
@@ -0,0 +1,70 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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.
+
+
+from mistral.workbook import base
+
+
+class TaskSpec(base.BaseSpec):
+    _required_keys = ['name', 'action']
+
+    def __init__(self, task):
+        super(TaskSpec, self).__init__(task)
+        self._prepare(task)
+        if self.validate():
+            self.requires = task['requires']
+            self.action = task['action']
+            self.name = task['name']
+            self.parameters = task.get('parameters', {})
+
+    def _prepare(self, task):
+        if task:
+            req = task.get("requires", {})
+            if req and isinstance(req, list):
+                task["requires"] = dict(zip(req, ['']*len(req)))
+            elif isinstance(req, dict):
+                task['requires'] = req
+
+    def get_property(self, property_name, default=None):
+        return self._data.get(property_name, default)
+
+    def get_on_error(self):
+        task = self.get_property("on-error")
+        if task:
+            return task if isinstance(task, dict) else {task: ''}
+        return None
+
+    def get_on_success(self):
+        task = self.get_property("on-success")
+        if task:
+            return task if isinstance(task, dict) else {task: ''}
+        return None
+
+    def get_on_finish(self):
+        task = self.get_property("on-finish")
+        if task:
+            return task if isinstance(task, dict) else {task: ''}
+        return None
+
+    def get_action_service(self):
+        return self.action.split(':')[0]
+
+    def get_action_name(self):
+        return self.action.split(':')[1]
+
+
+class TaskSpecList(base.BaseSpecList):
+    item_class = TaskSpec
diff --git a/mistral/workbook/workbook.py b/mistral/workbook/workbook.py
new file mode 100644
index 000000000..b1f67bf99
--- /dev/null
+++ b/mistral/workbook/workbook.py
@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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.
+
+from mistral.workbook import base
+from mistral.workbook import services
+from mistral.workbook import workflow
+
+
+class WorkbookSpec(base.BaseSpec):
+    _required_keys = ['Services', 'Workflow']
+
+    def __init__(self, doc):
+        super(WorkbookSpec, self).__init__(doc)
+        if self.validate():
+            self.services = services.ServiceSpecList(self._data['Services'])
+            self.workflow = workflow.WorkflowSpec(self._data['Workflow'])
+            self.tasks = self.workflow.tasks
+
+    def get_triggers(self):
+        triggers_from_data = self._data.get("triggers", None)
+        if not triggers_from_data:
+            return []
+        triggers = []
+        for name in triggers_from_data:
+            trigger_dict = {'name': name}
+            trigger_dict.update(triggers_from_data[name])
+            triggers.append(trigger_dict)
+        return triggers
+
+    def get_action(self, task_action_name):
+        if task_action_name.find(":") == -1:
+            return {}
+        service_name = task_action_name.split(':')[0]
+        action_name = task_action_name.split(':')[1]
+        action = self.services.get(service_name).actions.get(action_name)
+        return action
+
+    def get_actions(self, service_name):
+        return self.services.get(service_name).actions
+
+    def get_event_task_name(self, event_name):
+        event = self._data["Workflow"]["events"].get(event_name)
+        return event.get('tasks') if event else ""
diff --git a/mistral/workbook/workflow.py b/mistral/workbook/workflow.py
new file mode 100644
index 000000000..f670fd5c3
--- /dev/null
+++ b/mistral/workbook/workflow.py
@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2013 - Mirantis, Inc.
+#
+#    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.
+
+from mistral.workbook import base
+from mistral.workbook import tasks
+
+
+class WorkflowSpec(base.BaseSpec):
+    _required_keys = ['tasks']
+
+    def __init__(self, workflow):
+        super(WorkflowSpec, self).__init__(workflow)
+        if self.validate():
+            self.tasks = tasks.TaskSpecList(workflow['tasks'])