report_invoice_utility/view/report_invoice_utility.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
  <data>

    <record id="account_invoice_utility"  model="ir.actions.act_window">
        <field name="name">Analisis de Utilidad</field>
        <field name="res_model">report.invoice.utility</field>
        <field name="view_type">form</field>
        <field name="view_mode">tree</field>
    </record>


    <record id="account_invoice_utility_tree" model="ir.ui.view">
            <field name="name">account.invoice.utility.tree</field>
            <field name="model">report.invoice.utility</field>
            <field name="view_type">tree</field>
            <field name="arch" type="xml">
              <tree ditable='bottom' delete='false' create='false'>
                  <field name="number" string="Factura"/>
                  <field name="name" string="Pordcuto"/>
                  <field name="quantity" sum="quantity"/>
                  <field name='standard_price' string="Precio de Costo" sum="standard_price"/>
                  <field name='price_unit' string="Precio Venta" sum="price_unit" />
                  <field name="cost_subtotal" string="Total Costo" sum="cost_subtotal" />
                  <field name='price_subtotal' string="Total Venta" sum="price_subtotal"/>
                  <field name='utilidad' string="utilidad" sum="utilidad"/>
              </tree>
            </field>
      </record>



    <menuitem id="invoice_utility" name="Analisis de Utilidad" parent="account.menu_finance_reports"/>
    <menuitem id="invoice_utility_menu" name="Analisis de Utilidad de Ventas" action="account_invoice_utility" parent="invoice_utility"/>

  </data>
</openerp>