Hi Simon,

Firstly you will need to add a related field in the mrp.bom object pointing toward the field 'qty_available' of the product.product object. Secondly you will need to add this new field in the tree view of mrp.bom.

According to how familiar you are with OpenERP and how you are using it you can do that either by the web interface in Settings/Database Structure and Settings/User Interface or by creating a new module.

Sorry but I am not so familiar with the web interface Database Structure menu. And so I could not find how to implement the related field this way. I am pretty sure it should be possible... Nevertheless you can still create a new python module with: your_module.py :

# -*- encoding: utf-8 -*-
from openerp.osv import fields, osv

class mrp_bom(osv.osv):
    _inherit = "mrp.bom"
    _columns = {
                'qty_available': fields.related('product_id', 'qty_available', type="float", relation="product.product", string="Qty on hand")}

and a your_module_view.xml:

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

        <record id="mrp_bom_component_qty_tree_view" model="ir.ui.view">
            <field name="name">mrp.bom.component.qty.tree</field>
            <field name="model">mrp.bom</field>
            <field name="inherit_id" ref="mrp.mrp_bom_component_tree_view" />
            <field name="sequence" eval="10" />
            <field name="arch" type="xml">
                <xpath expr="//field[@name='product_qty']" position="after">
                        <field name="qty_available" />
                </xpath>
            </field>
        </record>

    </data>
</openerp>