diff --git a/addons/crm/doc/changelog.rst b/addons/crm/doc/changelog.rst
index cb1602a8d39..e9bd1980956 100644
--- a/addons/crm/doc/changelog.rst
+++ b/addons/crm/doc/changelog.rst
@@ -6,6 +6,12 @@ Changelog
 `trunk (saas-2)`
 ----------------
 
+- Stage/state update
+
+  - ``crm.lead``: removed ``state`` field. Added ``date_last_stage_update`` field
+    holding last stage_id modification. Updated reports.
+  - ``crm.case.stage``: removed ``state`` field.
+
 - ``crm``, ``crm_claim``: removed inheritance from ``base_stage`` class. Missing
   methods have been added into ``crm`` and ``crm_claim``. Also removed inheritance
   in ``crm_helpdesk`` because it uses states, not stages.
\ No newline at end of file
diff --git a/addons/crm/doc/index.rst b/addons/crm/doc/index.rst
index d70e045befe..f98ca145a56 100644
--- a/addons/crm/doc/index.rst
+++ b/addons/crm/doc/index.rst
@@ -4,6 +4,11 @@ CRM module documentation
 CRM documentation topics
 '''''''''''''''''''''''''
 
+.. toctree::
+   :maxdepth: 1
+   
+   stage_status.rst
+
 Changelog
 '''''''''
 
diff --git a/addons/crm/doc/stage_status.rst b/addons/crm/doc/stage_status.rst
new file mode 100644
index 00000000000..ca5d3d3d6e1
--- /dev/null
+++ b/addons/crm/doc/stage_status.rst
@@ -0,0 +1,61 @@
+.. _stage_status:
+
+Stage and Status
+================
+
+.. versionchanged:: 8.0 saas-2 state/stage cleaning
+
+Stage
++++++
+
+This revision removed the concept of state on crm.lead objects. The ``state``
+field has been totally removed and replaced by stages, using ``stage_id``. The
+following models are impacted:
+
+ - ``crm.lead`` now use only stages. However conventions still exist about
+   'New', 'Won' and 'Lost' stages. Those conventions are:
+
+   - ``new``: ``stage_id and stage_id.sequence = 1``
+   - ``won``: ``stage_id and stage_id.probability = 100 and stage_id.on_change = True``
+   - ``lost``: ``stage_id and stage_id.probability = 0 and stage_id.on_change = True
+     and stage_id.sequence != 1``
+
+ - ``crm.case.stage`` do not have any ``state`` field anymore. 
+ - ``crm.lead.report`` do not have any ``state`` field anymore. 
+
+By default a newly created lead is in a new stage. It means that it will
+fetch the stage having ``sequence = 1``. Stage mangement is done using the
+kanban view or the clikable statusbar. It is not done using buttons anymore.
+
+Stage analysis
+++++++++++++++
+
+Stage analysis can be performed using the newly introduced ``date_last_stage_update``
+datetime field. This field is updated everytime ``stage_id`` is updated.
+
+``crm.lead.report`` model also uses the ``date_last_stage_update`` field.
+This allows to group and analyse the time spend in the various stages.
+
+Open / Assignation date
++++++++++++++++++++++++
+
+The ``date_open`` field meaning has been updated. It is now set when the ``user_id``
+(responsible) is set. It is therefore the assignation date.
+
+Subtypes
+++++++++
+
+The following subtypes are triggered on ``crm.lead``:
+
+ - ``mt_lead_create``: new leads. Condition: ``obj.probability == 0 and obj.stage_id
+   and obj.stage_id.sequence == 1``
+ - ``mt_lead_stage``: stage changed. Condition: ``(obj.stage_id and obj.stage_id.sequence != 1)
+   and obj.probability < 100``
+ - ``mt_lead_won``: lead/oportunity is won. condition: `` obj.probability == 100
+   and obj.stage_id and obj.stage_id.on_change``
+ - ``mt_lead_lost``: lead/opportunity is lost. Condition: ``obj.probability == 0
+   and obj.stage_id and obj.stage_id.sequence != 1'``
+
+
+Those subtypes are also available on the ``crm.case.section`` model and are used
+for the auto subscription.