******
Design
******

The *Purchase Price List Module* extends the following concepts:

.. _model-party.party:

Party
=====

When the *Purchase Price List Module* is activated, `Price List
<product_price_list:model-product.price_list>` can also be defined for use with
purchases from the party.

.. seealso::

   The `Party <party:model-party.party>` concept is introduced by the module
   :doc:`Party Module <party:index>`.

.. _model-purchase.purchase:

Purchase
========

When the *Purchase Price List Module* is activated, the unit price of a product
is calculated using the `Price List
<product_price_list:model-product.price_list>` if one is defined for the
supplier and if the `Product <product:model-product.product>` does not have a
`Product Supplier Price <purchase:model-purchase.product_supplier.price>`.


.. seealso::

   The `Purchase <purchase:model-purchase.purchase>` concept is introduced by
   the module :doc:`Purchase Module <purchase:index>`.