[ADD] inventory: How to integrate landed costs in the cost of the product?

https://docs.google.com/document/d/1oDeU3ZwGnS1vrxyOqx0O_XvwQeI4crIymuIJaFBkSAk/edit#

inventory/routes/costing/landed_costs.rst

@@ -1,3 +1,81 @@
-==========================================================
+=========================================================
-How to setup a perpetual FIFO or LIFO inventory valuation?
+How to integrate landed costs in the cost of the product?
-==========================================================
+=========================================================
+
+Overview
+========
+
+Landed costs include all charges associated to a good transfer.
+
+Landed cost includes = Cost of product + Shipping + Customs + Risk
+
+All of these components might not be applicable in every shipment, but
+relevant components must be considered as a part of the landed cost. We
+have to identify landed cost to decide sale price of product because it
+will impact on company profits.
+
+Configuration
+=============
+
+Applications configuration
+--------------------------
+
+First, you need to activate the use of the landed costs. Go to
+:menuselection:`Inventory application --> Configuration --> Setting`. 
+Check accounting option **Include landed costs in product costing computation**
+& **Perpetual inventory valuation**, then click on **Apply** to save
+changes.
+
+.. image:: media/landed_costs01.png
+    :align: center
+
+Then go to the :menuselection:`Purchase application --> Configuration --> Setting`.
+Choose costing method **Use a 'Fixed', 'Real' or 'Average' price
+costing method**, then click on **Apply** to save changes.
+
+.. image:: media/landed_costs02.png
+    :align: center
+
+Landed Cost Types
+-----------------
+
+Start by creating specific products to indicate your various **Landed
+Costs**, such as freight, insurance or custom duties. Go to 
+:menuselection:`Inventory --> Configuration --> Landed Cost types`.
+
+.. image:: media/landed_costs03.png
+    :align: center
+
+.. demo:fields:: stock_landed_costs.stock_landed_cost_type_action
+
+.. note:: 
+    Landed costs are only possible for products configured in real
+    time valuation with real price costing method. The costing method is
+    configured on the product category.
+
+Link landed costs to a transfer
+===============================
+
+To calculate landed costs, go to 
+:menuselection:`Inventory --> Inventory Control --> Landed Costs`.
+
+Click on the **Create** button and select the picking(s) you want to
+attribute landed costs.
+
+.. image:: media/landed_costs04.png
+    :align: center
+
+Select the account journal in which to post the landed costs. We
+recommend you to create a specific journal for landed costs. Therefore
+it will be easier to keep track your postings.
+
+.. image:: media/landed_costs05.png
+    :align: center
+
+Click the **Compute** button to see how the landed costs will be split
+across the picking lines.
+
+.. image:: media/landed_costs06.png
+    :align: center
+
+To confirm the landed costs attribution, click on the **Validate** button.