<?xml version="1.0"?>
<openerp>
    <data noupdate="1">
        <function model="*model_name*" name="_configure_sales"/>
    </data>
</openerp>

This simple xml file is calls _configure_sales function from model_name model.

NOTE: this xml file should be on the top of data array, because Odoo is processiong xml files from top to bottom.

class *model_name*(models.Model):
    _name = *model_name*

    @api.model
    def _configure_sales(self):
        # Do the configuration here

Every time when module will be installed this function will run.

Note: If you remove noupdate from xml, function will run on upgrading as well.