[ADD] MRP: Unbuild orders

closes odoo/documentation#8264

Signed-off-by: Samuel Lieber (sali) <sali@odoo.com>

content/applications/inventory_and_mrp/manufacturing/management.rst

@@ -20,6 +20,7 @@ Manufacturing workflows
    management/configure_manufacturing_product
    management/split_merge
    management/work_order_dependencies
+   management/unbuild_orders
    management/one_step_manufacturing
    management/two_step_manufacturing
    management/three_step_manufacturing

content/applications/inventory_and_mrp/manufacturing/management/unbuild_orders.rst

@@ -0,0 +1,90 @@
+==============
+Unbuild orders
+==============
+
+.. |BoM| replace:: :abbr:`BoM (Bill of Materials)`
+
+In some cases, it is necessary to dismantle manufactured products into their individual components.
+This may be required if too many units of a product were built, or if the components of one product
+must be reclaimed to use in the manufacturing of another.
+
+In Odoo *Manufacturing*, products can be dismantled, and their components returned to inventory,
+using *unbuild orders*. By using unbuild orders to accomplish this task, inventory counts for the
+finished product and its components remain accurate, based on the quantity of products dismantled,
+and the quantity of components reclaimed.
+
+Create unbuild order
+====================
+
+A new unbuild order can be created by navigating to :menuselection:`Manufacturing app --> Operations
+--> Unbuild Orders`, and clicking :guilabel:`New`.
+
+Begin filling out the new unbuild order by selecting a :guilabel:`Product` to unbuild. After doing
+so, the :guilabel:`Bill of Material` field auto-populates with the corresponding bill of materials
+(BoM). If a different |BoM| should be used, click on the :guilabel:`Bill of Material` field, and
+select it from the drop-down menu.
+
+Alternatively, a specific |BoM| can be selected in the :guilabel:`Bill of Material` field before
+selecting a product, which causes the corresponding product to auto-populate in the
+:guilabel:`Product` field.
+
+Next, specify the :guilabel:`Quantity` of the product that is being unbuilt.
+
+If the product being unbuilt was originally manufactured in a specific manufacturing order (MO),
+select it in the :guilabel:`Manufacturing Order` field.
+
+In the :guilabel:`Source Location` field, select the location where the product being unbuilt is
+currently stored.
+
+In the :guilabel:`Destination Location` field, select the location where the reclaimed components
+are stored after the unbuild order is completed.
+
+If the *Lots & Serial Numbers* feature is enabled in the settings of the *Inventory* app, a
+:guilabel:`Lot/Serial Number` field appears on the unbuild order, which can be used to specify the
+lot(s) or serial number(s) of the product being unbuilt, if any are assigned.
+
+If the Odoo database has been configured with multiple companies, a :guilabel:`Company` field
+appears on the unbuild order, which can be used to specify the company that owns the product being
+unbuilt.
+
+Finally, once the product has been unbuilt, click the :guilabel:`Unbuild` button at the top of the
+order to confirm that it has been completed.
+
+.. image:: unbuild_orders/unbuild-order.png
+   :align: center
+   :alt: A filled-out unbuild order.
+
+.. warning::
+   While it is possible to create unbuild orders for products that have zero (or fewer) units
+   on-hand, this is not advised, since it can lead to inventory inconsistencies.
+
+   If an unbuild order is created for a product with zero (or fewer) units on-hand, a pop-up window
+   appears, warning the user that there is an insufficient quantity to unbuild.
+
+   To ignore the warning, and proceed with the unbuild order, click :guilabel:`Confirm` at the
+   bottom of the pop-up window. To return to the unconfirmed unbuild order, click
+   :guilabel:`Discard`, instead.
+
+   .. image:: unbuild_orders/insufficient-quantity.png
+      :align: center
+      :alt: The insufficient quantity pop-up that appears after trying to confirm an unbuild order
+            for a product with zero or fewer units on hand.
+
+After completing an unbuild order, inventory counts automatically update, based on the quantity of
+products unbuilt, and the quantity of components reclaimed.
+
+.. example::
+   A `Coat Rack` product is comprised of one `Wooden Pole` component and six `Wooden Dowel`
+   components.
+
+   An unbuild order is created for one unit of the `Coat Rack`. Once the order is completed, the
+   on-hand quantity of `Coat Racks` decreases by one, while the on-hand quantities of `Wooden Poles`
+   and `Wooden Dowels` increase by one and six, respectively.
+
+Scrap unusable components
+=========================
+
+In some cases, components may be unusable after the unbuilding process is completed. To ensure that
+inventory counts accurately reflect the quantity of usable components on-hand, any component that
+can no longer be used should be removed from inventory using a :doc:`scrap order
+<../../inventory/product_management/product_replenishment/scrap_inventory>`.