[IMP] update content of "Invoicing policy" (Sales - V13) (#558)

sales/invoicing/invoicing_policy.rst

@@ -2,48 +2,80 @@
 Invoice based on delivered or ordered quantities
 ================================================
 
-Depending on your business and what you sell, you have two options for
-invoicing:
+Different business policies might require different options for invoicing:
 
-- Invoice on ordered quantity: invoice the full order as soon as the sales
-  order is confirmed.
-- Invoice on delivered quantity: invoice on what you delivered even if
-  it's a partial delivery.
+- The **Invoice what is ordered** rule is used as **default mode** in Odoo Sales, which means that
+  customers will be invoiced once the sales order is confirmed.
 
-Invoice on ordered quantity is the default mode.
+- The **Invoice what is delivered** rule will invoice customers once the delivery is done. This rule
+  concerns businesses that sell materials, liquids or food in large quantities. In these cases, the
+  quantity might diverge a little bit and it is, therefore, preferable to invoice the quantity
+  actually delivered.
 
-The benefits of using *Invoice on delivered quantity* depends on your
-type of business, when you sell material, liquids or food in large
-quantities the quantity might diverge a little bit and it is therefore
-better to invoice the actual delivered quantity.
+Being able to have different invoicing options allow you more flexibility. Indeed, you need to know
+exactly how to invoice your customers for different situations.
+
+Activate these features
+=======================
+
+Go to :menuselection:`Sales --> Configuration --> Settings` and under **Invoicing policy** choose
+the rule you want to apply.
+
+.. image:: media/invoicing_policy_1.png
+   :align: center
+   :class: img-thumbnail
+   :alt: How to choose your invoicing policy on Odoo Sales?
+
+.. important::
+   If you decide to choose the **Invoice what is delivered** rule, you will not be able to
+   activate the feature called **Automatic invoice**, which automatically generates invoices when
+   the online payment is confirmed.
+
+Choose an invoicing policy on a product form
+============================================
+
+From any product page, under the **Sales tab**, you will find the invoicing policy, which can be
+manually changed.
+
+.. image:: media/invoicing_policy_5.png
+   :align: center
+   :class: img-thumbnail
+   :alt: How to change your invoicing policy on a product form on Odoo Sales?
+
+Impact on sales flow
+====================
+
+On Odoo Sales, the basic sales flow will be to create a quotation, send it to your customer,
+wait for confirmation, confirm the sales order and create an invoice.
+
+- **Invoice what is ordered**: No impact on this basic sales flow. Indeed, you can invoice as soon
+  as the sale is confirmed.
+
+- **Invoice what is delivered**: Small impact on sales flow because you will have to manually
+  enter the delivered quantity on the sales order or to install the **Inventory App** to confirm the
+  delivered quantity before creating an invoice, with the **Sales App**. Indeed, if you try to
+  create an invoice without validating the delivered quantity, you will receive an error message as
+  below.
+
+  .. image:: media/invoicing_policy_3.png
+     :class: img-thumbnail
+     :alt: How the choice of your invoicing policy impacts your sales flow on Odoo Sales?
 
 .. note::
-    You also have the ability to invoice manually, letting you
-    control every options: invoice ready to invoice lines, invoice a
-    percentage (advance), invoice a fixed advance.
+   Once the quotation is confirmed and that the status went from **Quotation sent** to
+   **Sales order**, you are able to see your delivered and invoiced quantities directly from your
+   sales order (it is true for both rules).
 
-Decide the policy on a product page
-===================================
+   .. image:: media/invoicing_policy_4.png
+      :align: center
+      :class: img-thumbnail
+      :alt: How to see your delivered and invoiced quantities on Odoo Sales?
 
-From any products page, under the invoicing tab you will find the
-invoicing policy and select the one you want.
+   Odoo will automatically add the quantities to the invoice (even if it is a partial delivery).
 
-.. image:: media/invoicing_policy01.png
-    :align: center
+Finally, to create an invoice, you will have different possibilities: regular invoice or down
+payment (percentage or fixed amount).
 
-Send the invoice
-================
-
-Once you confirm the sale, you can see your delivered and invoiced
-quantities.
-
-.. image:: media/invoicing_policy02.png
-    :align: center
-
-If you set it in ordered quantities, you can invoice as soon as the sale
-is confirmed. If however you selected delivered quantities, you will
-first have to validate the delivery.
-
-Once the products are delivered, you can invoice your customer. Odoo
-will automatically add the quantities to invoice based on how many you
-delivered if you did a partial delivery.
+.. important::
+   Be sure to check out our documentation about down payment here: :doc:`down_payment`, to master
+   this incredible feature.