[ADD] purchase: How to manage multiple offers

Converted from https://docs.google.com/document/d/1ApPHgeehy2AiqLgZm2NT9MqFe_q_sfd5DNKzI44nlQs/edit#

purchase/purchases/tender/manage_multiple_offers.rst

@@ -2,3 +2,137 @@
 How to manage multiple offers from suppliers with purchase tenders?
 ===================================================================
 
+A **Purchase Tender** (PT), also known as Call for Bids, is used to
+drive competition between several suppliers in order to get the best
+offer for a list of products. In comparison to the RfQ, a Purchase
+Tender is sent to multiple suppliers, stating each are competing with
+one another, and that the best offer will win. The main interest is that
+it usually leads to better offers.
+
+For more information on best uses, please read the chapter :doc:`../../overview/difference`
+
+Configuration
+=============
+
+Activating the Purchase Tender function
+---------------------------------------
+
+By default, the Purchase Tender is not activated. To be able to use PTs,
+you must first activate the option.
+
+In the Purchases module, open the Configuration menu and click on
+Settings. In the Purchase Order section, locate the **Calls for
+Tenders** and tick the box Allow using call for tenders… (advanced),
+then click on **Apply**.
+
+.. image:: ./media/image16.png
+	:align: center
+
+Creating a Purchase Tender
+--------------------------
+
+To create a new Purchase Tender, open :menuselection:`Purchase --> Purchase Tenders`.
+
+.. image:: ./media/image19.png
+	:align: center
+
+In the Purchase Tenders window, click on **Create**. A new Purchase Tenders
+window opens.
+
+By default, Odoo names PTs "TEXXXXX" but you can change it as you like.
+
+.. image:: ./media/image21.png
+	:align: center
+
+In the **Responsible** field, you can select the person who will be in
+charge of the PT.
+
+In the **Tender Selection Type** menu, you can decide to:
+
+- select only one RfQ and automatically cancel all other bid: *Select only one RFQ (exclusive)*
+
+- allow multiple purchase orders for this PT: *Select multiple RFQ*
+
+Tick in the box **Multiple RFQ per vendor** if you wish to allow
+suppliers to send in more than one Request for Quotation.
+
+.. image:: ./media/image18.png
+	:align: center
+
+In the **Tender Closing Deadline** field, select the date to bids are
+closed for suppliers.
+
+In the **Scheduled Ordering Date** field, select the date to which you
+will place the order.
+
+In the **Scheduled Date** field, select the date to which the products
+should be delivered.
+
+In the **Source Document** field, you can insert a previous PO to use as
+a template.
+
+.. image:: ./media/image15.png
+	:align: center
+
+In the Products section, click on **Add an item**.
+
+Select the product in the **Product** list, then insert **Quantity**.
+You can add as many products as you wish.
+
+.. image:: ./media/image04.png
+	:align: center
+
+Click on **Save**, then on **Confirm Call**. Two new RFQs/Bids and Request a
+Quotation tabs have appeared on the right side of the window.
+
+.. image:: ./media/image17.png
+	:align: center
+
+Click on **Request a Quotation** and type in the names of the suppliers you
+wish to include in the PT, then click on **Create Request for Quotation**.
+
+.. image:: ./media/image12.png
+	:align: center
+
+A list of suppliers has appeared in the **Requests for Quotation**
+section.
+
+.. image:: ./media/image09.png
+	:align: center
+
+To send the RfQs to your suppliers, click on the green V icon. You can
+also review the RfQ before sending them by clicking on them.
+
+When you receive offers, click on the RFQs/Bids tab. In the list view,
+select the company and click on **Edit** to adapt the details as stated in
+the offer.
+
+.. image:: ./media/image20.png
+	:align: center
+
+When you have edited all the corresponding fields, click on **Save**.
+
+When the deadline has been reached, click on **Close Call for Tenders**. The
+status of the PT is now **Bid Selection**. Open the RFQs/Bids tab and open
+the RfQ(s) you wish to proceed with.
+
+.. image:: ./media/image14.png
+	:align: center
+
+Click on **Approve Order** to convert the RfQ into a Purchase Order, the go
+back to your PT and click on **Done** to close the PT.
+
+.. demo:action:: purchase_requisition.action_purchase_requisition
+
+   View *Purchase Tenders* in our Online Demonstration
+
+.. seealso:: 
+
+	:doc:`../../overview/from_po_to_invoice`
+
+	:doc:`../../overview/difference`
+
+.. rst-class:: text-muted
+
+| Written by Samuel Cabodi (Odoo)
+| Proofread by Geoffrey Bressan (Odoo)