eiru_sale_machine/views/sale_order_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="sale_order_form_view_inherit_product_empl" model="ir.ui.view">
            <field name="name">sale.order.form.inherit</field>
            <field name="model">sale.order</field>
            <field name="inherit_id" ref="sale.view_order_form"/>
            <field name="arch" type="xml">

                <xpath expr="//field[@name='order_line']/tree/field[@name='name']" position="after">
                    <field name="mrp_machine_id" attrs="{'readonly': [('state', 'in', ('sale','done', 'cancel'))]}"/>
                </xpath>
            </field>
        </record>

    </data>
</openerp>